HomeMy WebLinkAboutResolution 2020-070
EXHIBIT A
ADDENDUM TO FINAL ENVIRONMENTAL IMPACT REPORT –
Del Rio Road Commercial Area Specific Plan
(Certified by the Atascadero City Council on June 26, 2012)
1.1 INTRODUCTION
The California Environmental Quality Act (CEQA) requires public agencies to analyze and
consider the environmental consequences of decisions to approve development projects
that they exercise discretion over. CEQA achieves this objective by requiring agencies to
prepare Environmental Impact Reports (EIR’s) for projects with the potential to cause
significant impacts on the physical environment. EIR’s are public documents that analyze
environmental effects related to the planning, construction, and operation of a project,
and indicate ways to reduce or avoid possible environmental damage. An EIR also
discloses growth-inducing impacts, effects found not to be significant, significant
cumulative impacts, and significant impacts that cannot be avoided, if any. The purpose
of an EIR is to inform. EIR’s are not policy documents that recommend project approval
or denial.
As a lead agency, the City of Atascadero prepared an Environmental Impact Report (EIR)
for the Del Rio Road Commercial Area Specific Plan in compliance with the California
Environmental Quality Act (CEQA) (Public Resources Code, section 21000 et seq.) and
the State CEQA Guidelines (California Code of Regulations, Section 15000 et seq., as
amended). The City Council certified the Final Environmental Impact Report (Final EIR)
for the Del Rio Road Commercial Area Specific Plan at a public hearing on June 26, 2012.
As noted in the Final EIR, the analysis in the Final EIR was at a “project” level of detail,
which anticipated the potential impacts of future approvals to implement the project.
Public Resources Code Section 21166 limits the ability of an agency to require an
additional EIR, once one has been certified for a project. Section 21166 provides as
follows:
§21166. Subsequent or Supplemental Impact Report; Conditions.
When an environmental impact report has been prepared for a project pursuant to this division, no
subsequent or supplemental environmental impact report shall be required by the lead agency or by any
responsible agency, unless one or more of the following events occurs:
(a). Substantial changes are proposed in the project which will require major revisions of the
environmental impact report.
(b). Substantial changes occur with respect to the circumstances under which the project is being
undertaken which will require major revisions in the environmental impact report.
(c). New information, which was not known and could not have been known at the time the
environmental impact report was certified as complete, becomes available.
The CEQA Guidelines further refine the circumstances under which a supplemental or
subsequent EIR may be required. Guidelines Section 15162 provides as follows:
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15162. Subsequent EIRs and Negative Declarations.
(a) When an EIR has been certified or negative declaration adopted for a project, no subsequent EIR
shall be prepared for that project unless the lead agency determines, on the basis of substantial evidence in
the light of the whole record, one or more of the following:
(1). Substantial changes are proposed in the project which will require major revisions of the
previous EIR or negative declaration due to the involvement of new significant environmental
effects or a substantial increase in the severity of previously identified significant effects;
(2). Substantial changes occur with respect to the circumstances under which the project is
undertaken which will require major revisions of the previous EIR or negative declaration due to
the involvement of new significant environmental effects or a substantial increase in the severity
of previously identified significant effects; or
(3). New information of substantial importance, which was not known and could not have been
known with the exercise of reasonable diligence at the time the previous EIR was certified as
complete or the negative declaration was adopted, shows any of the following:
(A). The project will have one or more significant effects not discussed in the previous
EIR or negative declaration;
(B). Significant effects previously examined will be substantially more severe than shown
in the previous EIR;
(C). Mitigation measures or alternatives previously found not to be feasible would in fact
be feasible and would substantially reduce one or more significant effects of the project,
but the project proponents decline to adopt the mitigation measure or alternative; or
(D). Mitigation measures or alternatives which are considerably different from those
analyzed in the previous EIR would substantially reduce one or more significant effects on
the environment, but the project proponents decline to adopt the mitigation measure or
alternative.
In 2017, the City amended the Del Rio Specific Plan to accommodate the Hilton Hotel on
the western portion of the “Annex” site of the Del Rio Specific Plan to allow for a hotel
instead of retail development. That amendment recognized a reduction in vehicle trips
and associated environmental impacts. A four-story, 120-room hotel, north of Del Rio
Road, between Hwy 101 and El Camino Real has been recently completed as a result of
that amendment.
In 2017, Walmart notified the City that they would no longer be pursuing the development
of their Del Rio store in Atascadero. In 2019, development plans were officially withdrawn
and the site is being marketed for sale. On July 12th, 2020, the tentative parcel map and
associated Master Plan of Development for the project expired. Based on the current
retail climate, it is anticipated that the local market will no longer support a large retailer
for this site and that other land uses may be more appropriate. Regardless of the
expiration of the project parcel map, the zoning of the site, which is Commercial Retail
with a portion of Multi-Family Residential remains in place as the Specific Plan does not
have an expiration date.
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In 2019 the City also received an amendment to the Master Plan of Development for the
eastern portion of the “Annex” retail site. The amendment proposed a change in the
development pattern of the site shifting from a retail focused center to a business park
and jobs centric development. All uses proposed with the amendment are allowed or
conditionally allowed within the underlying Commercial Retail (CR) zoning designation,
and are therefore, allowed do be developed within the Specific Plan area.
Based on these two changes within the boundaries of the Specific Plan, staff reviewed
the adopted Specific Plan and certified Final EIR to determine the level of additional
modification and CEQA analysis required. Before acting on the proposed amendments,
the Planning Commission and the City Council must apply the standards outlined above
to determine whether a subsequent or supplement EIR is required.
After reviewing the facts and analyzing the circumstances, City staff has determined that
a new EIR is not required because none of the circumstances described in CEQA Section
21166, as implemented by CEQA Guidelines Section 15162, would occur. Staff has
prepared an addendum to discuss these issues and the basis for this determination.
2.0 Del Rio Road / US 101 Interchange / Del Rio Road & El Camino Real
The certified Final EIR for the Del Rio Road Commercial Area Specific Plan included a
traffic analysis originally completed in 2010 for the Specific Plan, and later updated in
2012. It was the 2012 traffic study to which mitigation measures were crafted and adopted
as a part of the certified Final EIR. The Draft EIR contained mitigation measures that
required intersection improvements at El Camino Real / Del Rio Road and improvements
to the Del Rio Road / US 101 interchange. The Draft EIR analysis concluded the following:
The Del Rio Road / US Highway 101 interchange would have acceptable
levels of service following completion of a large retail store on the Wal-Mart
site;
The Del Rio Road / US Highway 101 interchange would have acceptable
operations with baseline (existing traffic, plus entitled projects with
construction time frames of 2-3 years circa 2012) plus large retailer;
The Del Rio Road / US Highway 101 interchange would have unacceptable
operations with existing traffic plus all proposed build-out of the Specific Plan
uses (including Annex properties);
The Del Rio Road / US Highway 101 interchange would have unacceptable
operations with baseline traffic plus all proposed build-out of the Specific Plan.
The City received a comment letter from the Department of Transportation (Caltrans) in
.
regards to proposed mitigation in the Draft EIR. Caltrans’ comments included the
following:
Caltrans Letter to City – Del Rio Road Draft EIR 4/30/2012
Based on this comment letter received from Caltrans, the Final EIR included an errata to
the identified mitigation measures with specific timing mechanisms for the completion of
Del Rio Road / US Highway 101 interchange improvements. Therefore, the Final EIR
contained mitigation measures that read as follows:
MM TRANS-1d – Prior to issuance of each building permit for the project, the project applicant
shall provide the City of Atascadero with proportional-share fees for the conversion of the
intersection of Del Rio Road/US 101 Northbound Ramps to a single-lane modern roundabout with
a minimum 150-foot-long, right-turn bypass lane on the westbound approach. The traffic impact
fee shall be based on the size of the building subject to the building permit and shall be consistent
with the proportional share methodology prepared by RCS as described in the “TIF Collection
Process” discussion in Section 3.11, Transportation. The City of Atascadero shall collect the fees
and shall be responsible for constructing the roundabout improvements. Implementation of the
northbound and southbound roundabouts shall occur in tandem. The roundabout shall be in place
no later than the issuance of the first certificate of occupancy for the Annex commercial uses.
MM TRANS-1e – Prior to issuance of each building permit for the project, the project applicant
shall provide the City of Atascadero with proportional-share fees for the construction of a five-
legged, single-lane modern roundabout at the intersection of Del Rio Road/US 101 Southbound
Ramps that incorporates Ramona Road as the fifth approach. The traffic impact fee shall be based
on the size of the building subject to the building permit and shall be consistent with the
proportional share cost methodology prepared by RCS as described in the “TIF Collection
Process” discussion in Section 3.11, Transportation. The City of Atascadero shall collect the fees
and shall be responsible for constructing the roundabout improvements. Implementation of the
northbound and southbound roundabouts shall occur in tandem. The roundabout shall be in place
no later than the issuance of the first certificate of occupancy for the Annex commercial uses.
The City Council certified the Final EIR with this updated mitigation language. The
mitigation was silent on the establishment of traffic thresholds (# of trips) for completion
of improvements. The timing of the improvements was instead tied to specific
development sites, therefore allowing Walmart to proceed and requiring the Annex to wait
for completion of the complete interchange improvements, which included two
roundabouts at both the northbound and southbound ramps.
The Walmart and Annex developments were conditioned to pay their fair share (53% of
the estimated interchange roundabout costs) through traffic impact fees. These impact
fees were calculated based upon a cost estimate of $4.5 million at time of approval (March
2012). This estimate was reviewed by several engineers and seemed on par with other
estimates and other actual costs for similar roundabout projects provided to the City at
that time.
In addition to these special roundabout mitigation fees, both Walmart and the Annex were
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further conditioned to pay the City’s Standard Traffic Impact Fees (TIF) and to pay a
maximum of $200,000 each toward cost overruns if necessary. Overall, the Walmart and
Annex are conditioned to pay about $5.3 million in TIF to the City. This averages to about
$20.66 per square foot in Traffic Impact Fees.
The Walmart project was also responsible for constructing a third roundabout at El
Camino Real (ECR)/Del Rio Road, installing a new signal light at ECR and San Anselmo
Road (East), improving a half-mile of ECR as a 4-lane arterial road, improving 1,000 feet
of Del Rio Road, and installing amenities such as an enhanced transit stop, Class II bike
lanes, street landscaping, and sidewalks.
The City began the Caltrans process for the Del Rio Road/US 101 Interchange Project in
November 2012 when Wallace Group was hired to perform the Project Initiation
Document (PID) phase with Caltrans.
With the mitigation measures as adopted, the EIR assumed construction and completion
of the Walmart store prior to any other development within the Specific Plan area.
However, this has not been the case. In 2017, an owner within the Annex portion of the
Specific Plan area applied for the construction of a 120 room hotel. Analysis showed a
decrease in traffic impacts and the development was permitted to proceed following an
amendment to the Master Plan of Development and Addendum to the FEIR.
In 2019 and 2020, following Walmart’s cancelation of the Atascadero store and submittal
of the Annex site Master Plan of Development amendment, staff consulted with W -trans
to complete a traffic sensitivity analysis of the Del Rio Road Interchange corridor to assess
the intensity of development that can be accommodated in the vicinity of the Del Rio Road
interchange while maintaining acceptable operations and identify final buildout
configurations. New future growth assumptions were factored in as well as updated
regional modeling to ensure the most accurate impact analysis.
The July 2020 Analysis considered the following:
1. In addition to a higher-altitude evaluation of the traffic generated by predictive land
use development scenarios completed in 2019, the 2020 analysis incorporated
regional growth and 20-year forecast scenarios in order to allow Caltrans to
determine long-range impacts to their facilities and ensure informed future
planning efforts.
2. The analyses investigated the traffic signal configurations, roadway geometrics, and
right-of-way impacts including delay time and queue length. The 2020 analysis
concluded that the mitigation measures proposed (detailed below) are feasible and
appropriate to the impacts.
3. Caltrans owns and operates the two traffic signals at the ramp intersections of Del
Rio and US 101. Caltrans priority will be mainline traffic operations on US 101 and
ensuring exiting traffic does not queue onto the mainline traffic lanes from off ramps.
The analyses studied the timing of the traffic signals and ramp queuing in
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preparation for coordinating with Caltrans on implementing the proposed mitigation
measures.
Land Use Scenarios
The Annex-West hotel project has recently been completed, and staff has had further
discussions with surrounding property owners, both within and outside the Specific Plan
boundaries, to get better clarity on likely land uses. Two Specific Plan land use scenarios
were developed and analyzed based on this information. Scenario 1 (Amended Specific
Plan/Table 5) includes a realistic buildout of the Specific Plan and surrounding area that
includes business park, small retail, and tourist based uses. Scenario 2 (Amended
Specific Plan with Regional Shopping Center/Table9) maintains a large scale retail use
on the former Walmart site to ensure informed planning for future improvements should
a higher traffic generating use be constructed within the Specific Plan boundary. Below
is a summary of the two land use scenarios and daily trip generation. Detailed traffic data
for each scenario can be found in the attachments.
Table 1 – Trip Generation Summary for Amended Specific Plan
Land Use Units Daily AM Peak Hour PM Peak Hour
Rate Trips Rate Trips In Out Rate Trips In Out
Annex West
Hotel 120 rms 8.36 1,003 0.47 56 33 23 0.60 72 37 35
Annex East
Business Park 190 ksf 12.44 2,364 0.40 76 46 30 0.42 80 37 43
Walmart Site
Warehousing 30 ksf 1.74 52 0.17 5 4 1 0.19 6 2 4
Sit-Down Restaurant 2 ksf 112.18 224 9.94 20 11 9 9.77 20 12 8
Pass-by -5% -11 -5% -1 -1 0 -5% -1 -1 0
Mixed Use Retail 15 ksf 37.75 566 0.94 14 9 5 3.81 57 27 30
Mixed Use
Residential
10 du 7.32 73 0.46 5 1 4 0.56 6 4 2
Light Industrial 30 ksf 12.44 373 0.40 12 7 5 0.42 13 6 7
Apartments 55 du 7.32 403 0.46 25 6 19 0.56 31 20 11
Internal Capture -5% -84 -5% -4 -2 -2 -5% -7 -4 -3
Subtotal 5,058 213 117 96 285 145 140
Reductions -95 -5 -3 -2 -8 -5 -3
Total 4,963 208 114 94 277 140 137
Note: rms = rooms; du = dwelling unit; ksf = 1,000 square feet
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Table 2 – Trip Generation Summary for Amended Specific Plan with Regional Shopping Center
Land Use Units Daily AM Peak Hour PM Peak Hour
Rate Trips Rate Trips In Out Rate Trips In Out
Annex West
Hotel 120 rms 8.36 1,003 0.47 56 33 23 0.60 72 37 35
Annex East
Business Park 190 ksf 12.44 2,364 0.40 76 46 30 0.42 80 37 43
Walmart Site
Regional Shopping Center 129.56 ksf 37.75 4,891 0.94 122 76 46 3.81 494 237 257
Sit-Down Restaurant 5 ksf 112.18 561 9.94 50 28 22 9.77 49 30 19
Pass-by -5% -28 -5% -3 -2 -1 -5% -2 -1 -1
Retail Pad 5 ksf 37.75 189 0.94 5 3 2 3.81 19 9 10
Apartments 55 du 7.32 403 0.46 25 6 19 0.56 31 20 11
Subtotal 9,411 334 192 142 745 370 375
Reductions -28 -3 -2 -1 -2 -1 -1
Total 9,383 331 190 141 743 369 374
Note: rms = rooms; du = dwelling unit; ksf = 1,000 square feet
Level of Service and Queue Length
The traffic demand during peak hours sets a basis for how much delay can be expected
at each intersection and how many vehicles queue (stack) in available queue length
storage leading up to the intersections. Delay and overall intersection performance is
measured in terms of Level of Service (LOS) from A through F based upon the number
of seconds it takes to get through an intersection. The following table summarizes the
LOS for traffic signalized intersections delay times.
LOS
Average Control Delay
(sec./vehicle)
Type of Traffic Flow
A 0 to 10 Stable
B >10 to 20 Stable
C >20 to 35 Stable
D > 35 to 55 Approaching Unstable
E >55 to 80 Unstable
F >80 Forced
It is important to note that State law changed in June 2020 and LOS is no longer the
metric used to determine traffic impacts for CEQA analyses. The State has shifted to a
focus on Vehicle Miles Traveled (VMT) as a more appropriate measure for traffic related
impacts to more accurately address correlated impacts on Greenhouse Gas Emissions.
While VMT has become the new standard for measuring impacts, the certified Final EIR
and current addendum analysis used LOS as the metric for determining traffic related
impacts and, under CEQA, that metric should be maintained for consistency and
understanding new impacts relative to past thresholds. While LOS will remain central to
the proposed amendments to the mitigation measures, qualitatively, VMT will be reduced
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with the amended specific plan land use scenario, especially considering the scenario
which eliminates the large regional retail use. A shift to head of household jobs and
resident serving retail will reduce VMT compared to the regional draw of a large-scale
retailer and regional based commercial center.
Queue length is more or less a pass/fail grade based upon whether there is enough
stacking capacity for vehicles to wait to pass through an intersection without spilling into
nearby lanes. Available queue lengths are measured for each intersection leg approach
and compared to the combined length of vehicles waiting in each lane.
The City’s General Plan Circulation Element Policy 1.3 addresses Level of Service as
follows:
“Maintain LOC C or better as the standard at all intersections and on all arterial
and collector roads. Upon City Council approval, accept LOS D where residences
are not directly impacted and improvements to meet the City’s standard would be
prohibitively costly or disruptive.”
W-Trans performed traffic analysis for each intersection to determine delay and queue
for traffic demand of existing + future regional growth + Amended Specific Plan (expected
development scenario) and Amended Specific plan with Regional Shopping Center (worst
case development scenario). This traffic demand was performed with the following
conditions:
Existing layout (no mitigations).
Mitigation 1 (M1) = Add westbound right-turn lane pocket to the intersection of Del
Rio/US 101North on-ramp.
Mitigation 2 (M2) = signal modifications at Del Rio/ECR including:
a. Signal interconnect and coordination for all locations.
b. ECR/Del Rio northbound left-turn: Replace protected movement with
protected + permissive movement
c. ECR/Del Rio southbound left-turn: Replace protected movement with
permissive movement
d. Modify eastbound and westbound to operate sequentially rather than at the
same time.
Mitigation 3 (M3) = Mitigation 1 and 2 combined
Mitigation 4 (M4) = Del Rio lane modifications to shift the coupling of the through
traffic movement from the left turn lane to the right turn lane and complete any
necessary lane realignments to accommodate the revised combination. In
addition, signal modifications and extension of interconnect hardware at the 101
interchange to the Del Rio/ECR intersection would be required.
Mitigation 5 (M5) = Widening of the Del Rio overpass and complete signal
modifications
The following tables summarizes the delays and queuing for both land use scenarios:
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Table 3 – Queuing Analysis (Amended Specific Plan)
Study Intersection
Approach
Available PM Peak Maximum Queue Length
Storage E F F + Amended Specific Plan
NM M1 M2 M3 M4
1. Del Rio Rd/El Camino Real
Northbound Left-Turn 280 155 286 397 374 250 256 221
Southbound Left-Turn 150 25 35 43 32 36 31 45
Southbound Right-Turn - - 76 91 81 92 94 111
Eastbound Approach 240 154 210 272 256 280 268 204
2. Del Rio Rd/US 101 N Ramps
Westbound Approach 240 84 148 202 96 215 93 58
Eastbound Approach 290 99 195 279 210 263 208 213
Northbound Approach 470 88 97 115 118 128 130 128
3. Del Rio Rd/US 101 S Ramps
Westbound Approach 290 98 132 132 138 127 137 284
Eastbound Approach – Exist 35 115 - - - - - -
Eastbound Approach – Future 240 - 111 119 118 134 125 166
Southbound Approach 530 192 362 539 445 333 366 323
4. Del Rio Rd/Ramona Rd
Westbound Approach – Exist 35 79 - - - - - -
Westbound Approach – Future 240 - 27 30 27 31 38 40
Notes: Maximum Queue based on the average of the maximum value from five SIMTRAFFIC runs; all distances
are measured in feet; E = existing conditions; F = future conditions; F+ASP = future plus Amended Specific
Plan conditions; NM = no mitigation; M1 = Mitigation 1; M2 = Mitigation 2; M3 = Mitigation 3; M4 =
Mitigation 4; Mitigations are described in the text above; Bold text = queue length exceeds available
storage
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Table 12 – Queuing Analysis (Amended Specific Plan plus Regional Shopping)
Study Intersection
Approach
Available PM Peak Maximum Queue Length
Storage E F F+ASP plus Regional Shopping
NM M1 M2 M3 M5
1. Del Rio Rd/El Camino Real
Northbound Left-Turn 280 155 286 330 330 330 396 181
Southbound Left-Turn 150 25 35 49 38 47 39 58
Southbound Right-Turn - - 76 91 97 90 117 97
Eastbound Approach 240 154 210 307 307 305 300 165
2. Del Rio Rd/US 101 N Ramps
Westbound Approach 240 84 148 267 134 270 151 54
Eastbound Approach 290 99 195 436 447 430 367 129
Northbound Approach 470 88 97 225 326 110 202 145
3. Del Rio Rd/US 101 S Ramps
Westbound Approach 290 98 132 157 163 154 188 116
Eastbound Approach – Exist 35 115 - - - - - -
Eastbound Approach – Future 240 - 111 145 150 151 123 172
Southbound Approach 530 192 362 1119 1196 1115 1218 331
4. Del Rio Rd/Ramona Rd
Westbound Approach – Exist 35 79 - - - - - -
Westbound Approach – Future 240 - 27 26 30 28 32 43
Notes: Maximum Queue based on the average of the maximum value from five SIMTRAFFIC runs; all distances
are measured in feet; E = existing conditions; F = future conditions; F+ASP = future plus Amended Specific
Plan; NM = no mitigation; M1 = Mitigation 1; M2 = Mitigation 2; M3 = Mitigation 3; M4 = Mitigation 4;
Mitigations are described in the text above; Bold text = queue length exceeds available storage
The above tables indicate that all intersections work acceptably with Mitigation 4 for the
Amended Specific Plan scenario, both from a level of service and adequate queue length
outcome. For the Amended Specific Plan plus Regional Shopping Center alternative,
Mitigation 5 would be required, which includes bridge widening at the Del Rio /Highway
101 overpass and associated signal modifications and lane reconfigurations. Additional
traffic information is included in Attachment 2.
Based on the supplemental traffic analysis findings, the addendum to the certified Final
EIR for the Del Rio Road Commercial Area Specific Plan proposes the following traffic
improvements modifications associated with the Del Rio/El Camino Real intersections as
well as the Del Rio/Highway 101 interchange. All amended language, including minor
changes for consistency, are included in Attachment 1.
Modifications to Del Rio Road Final EIR Mitigation Measures
Existing Mitigation Measure 1C:
MM TRANS-lc: Prior to issuance of the final certificate of occupancy for Walmart, the
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project applicant shall convert the intersection of Del Rio Road/El Camino Drive to a
modern roundabout. The roundabout shall provide an inscribed diameter of a minimum
of 160 feet and a combination of single and dual circulating lanes. Single-lane approaches
shall be adequate on the southbound and westbound entrances. The northbound
approach shall include a dual-lane entry with a left-only lane and a shared through/right-
turn lane. The eastbound approach shall include a shared through/left-turn lane and a
minimum 125-foot- long, right-turn lane. The City of Atascadero shall determine the
financial obligation of the applicant for the cost of the improvement, and the applicant
installing the improvement shall be eligible for a fee credit for the cost of these
improvements in excess of the project's proportional-share contribution.
Proposed Mitigation Measure 1C:
MM TRANS-lC: Prior to occupancy of the first new building within the Specific Plan on
the east side of El Camino Real, modifications to the traffic signal at Del Rio Road/El
Camino Real shall be completed by the developer to more efficiently orchestrate the
movement of conflicting traffic. This modification requires the replacement of the
northbound left-turn protected phasing (green arrow) with protected-permissive phasing
(green arrow that goes to green ball or flashing yellow arrow), and the southbound left-
turn protected phasing with permissive phasing (green ball or flashing yellow arrow). The
eastbound and westbound phases, which currently activate at the same time, shall be
split to operate sequentially, or one direction and then the other. These changes shall
require modification to the existing signal infrastructure to incorporate updated signal
heads. In addition, this mitigation includes adjustment to the signal phasing in terms of
recalls, phase lengths, and the overall cycle length.
The proposed mitigation language change for 1d will implement “Phase Two” mitigation
as follows:
Existing Mitigation Measure 1D:
MM TRANS-1d – Prior to issuance of each building permit for the project, the project applicant
shall provide the City of Atascadero with proportional-share fees for the conversion of the
intersection of Del Rio Road/US 101 Northbound Ramps to a single-lane modern roundabout with
a minimum 150-foot-long, right-turn bypass lane on the westbound approach. The traffic impact
fee shall be based on the size of the building subject to the building permit and shall be consistent
with the proportional share methodology prepared by RCS as described in the “TIF Collection
Process” discussion in Section 3.11, Transportation. The City of Atascadero shall collect the fees
and shall be responsible for constructing the roundabout improvements. Implementation of the
northbound and southbound roundabouts shall occur in tandem. The roundabout shall be in place
no later than the issuance of the first certificate of occupancy for the Annex commercial uses.
Proposed Mitigation Measure 1D:
Prior to occupancy of the first use that exceeds 134 p.m. cumulative peak hour trips, a
westbound right-turn lane shall be added to the intersection of Del Rio Road/US 101,
such that there would be two westbound lanes on Del Rio Road from El Camino Real to
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the US 101 North ramp. This would require widening Del Rio Road, the construction of
a retaining wall on the north side of Del Rio Road, and reconstruction of the curb return.
Concurrent with the addition of the right turn lane noted above, the intersection of Del Rio
Road/El Camino Real shall be reconfigured at the eastbound approach from through/left-
turn and right-turn lanes, to left-turn lane and through/right-turn lanes, moving the through
movement from the left lane to the right lane. This includes widening the eastbound
departure (on the east leg of the intersection) to avoid excessive lateral shifting of through
traffic. With a dedicated eastbound left-turn lane, the eastbound-westbound split phasing
shall be required to be replaced with concurrent timing, as well as protected-permissive
phasing for the eastbound left-turn movement. With protected left-turn phasing in the
eastbound direction and a prohibition of eastbound U-turns, a southbound right-turn
overlap shall be provided, which is a green arrow that enables southbound right-turning
drivers to continue without stopping concurrently with the eastbound left-turn movement.
Additionally, the signal at Del Rio Road/El Camino Real shall be coordinated with the
signals at Del Rio Road/US 101 North Ramps and Del Rio Road/US 101 South Ramps.
This will require extending the interconnect hardware between the ramp signals to Del
Rio Road/El Camino Real, and potentially upgrading the signal hardware at Del Rio
Road/El Camino Real to be compatible with interconnect technology if it is not already.
All development within the Specific Plan area shall be responsible for paying their fair
share towards these improvements as a special impact fee. The special impact fee will
be in addition to the Citywide impact fees in place at the time of development and shall
be collected prior to issuance of any permit. Should a developer construct the
improvements, any costs of the installed improvements in excess of the project’s
proportional share, may be eligible for a TIF fee credit. Any potential TIF fee credit will be
calculated by the City and will comply with any City resolution guiding TIF Fee credits in
place at the time of construction of the improvements. The developer constructing the
improvements may also be eligible for reimbursement from other development within the
Specific Plan area should improvements be installed prior to Specific Plan build-out.
Existing Mitigation Measure 1E:
MM TRANS-1e – Prior to issuance of each building permit for the project, the project applicant
shall provide the City of Atascadero with proportional-share fees for the construction of a five-
legged, single-lane modern roundabout at the intersection of Del Rio Road/US 101 Southbound
Ramps that incorporates Ramona Road as the fifth approach. The traffic impact fee shall be based
on the size of the building subject to the building permit and shall be consistent with the
proportional share cost methodology prepared by RCS as described in the “TIF Collection
Process” discussion in Section 3.11, Transportation. The City of Atascadero shall collect the fees
and shall be responsible for constructing the roundabout improvements. Implementation of the
northbound and southbound roundabouts shall occur in tandem. The roundabout shall be in place
no later than the issuance of the first certificate of occupancy for the Annex commercial uses.
Proposed Mitigation Measure 1E:
Prior to issuance of building permits for any land use that exceeds 293 cumulative
.
weekday p.m. peak hour trips within the Specific Plan area, the following improvements
shall be completed:
Widening the eastbound approach to Del Rio Road/El Camino Real to three lanes
that extend upstream to Del Rio Road/US 101 North Ramps, with one lane each
assigned to left turns, through lanes, and right turns.
The westbound approach shall be widened to include a right-turn pocket.
A second northbound left-turn lane shall be constructed to accommodate traffic
leaving the commercial developments and heading toward the freeway.
Overlaps shall be added to further improve traffic flow.
The Del Rio Road overpass shall to be widened to four lanes, with a through/left-
turn combined lane and through lane approaching eastbound to Del Rio Road/US
101 North Ramps and left-turn and through/left-turn combined lanes on the
westbound approach to Del Rio Road/US 101 South Ramps.
At Del Rio Road/US 101 South Ramps, the southbound approach shall be
expanded to include an additional left-turn lane, and the phasing shall be modified
to split the eastbound and westbound approaches.
Interconnect shall be provided between all three signals to coordinate cycles.
Should a developer construct the improvements, any costs of the installed improvements
in excess of the project’s proportional share, may be eligible for a TIF fee credit. Any
potential TIF fee credit will be calculated by the City and will comply with any City
resolution guiding TIF Fee credits in place at the time of construction of the
improvements. The developer constructing the improvements may also be eligible for
reimbursement from other development within the Specific Plan area should
improvements be installed prior to Specific Plan build-out.
Summary
The certified Final EIR, with the inclusion of mitigation measures in the certified Final EIR,
modified with input from Caltrans, concluded that, in order to mitigate impacts created by
the completion of the Del Rio Road Commercial Area Specific Plan, a new 5-legged
roundabout would be needed at the US 101 / Del Rio Road interchange. With the revised
land-use development scenarios including updated future regional impacts and future
anticipated development within the City, the new 2020 traffic analysis concluded that
construction of roundabouts is not warranted and that alternative mitigation strategies can
be implemented that will maintain functionality of the overpass and intersections.
With the revised land-use development scenarios for the Specific Plan area and updated
projections for local and regional growth, traffic impacts at the Del Rio / 101 interchange
and at the Del Rio / El Camino Real intersection decrease. The supplemental traffic
analyses show that there are no "new significant environmental effects or substantial
increase in the severity of previously identified significant effects." (Section 15162(a)(1))
2.1 Application of CEQA Guideline Section 15612
Is there substantial evidence in the record revealing that there have been substantial
changes proposed in the project which will require major revisions of the previous
.
EIR due to the involvement of new significant environmental effects or a substantial
increase in the severity of previously identified significant effects as a result of the
Master Plan of Development amendment and revised land use development
scenarios?
No. The City has completed extensive analyses of the revised traffic impacts based on
the modified land use development scenarios and the estimated foreseeable regional and
local future impacts. Under the anticipated land use scenario, the modified development
pattern will result in a decrease in traffic impacts, both at the interchange and local
intersection. As noted above, the previous EIR analyzed the impacts of the Specific Plan
Amendment with commercial retail uses throughout the majority of the project. The
proposed master plan of development amendment would include a 190,000 square foot
business park as opposed to the approved 120,900 sf of retail. With the supplemental
traffic analysis identifying uses in both the Specific Plan area, as well as an update to the
baseline and regional traffic modeling, impacts are decreased and mitigation is proposed
that responds to these changes. The Specific Plan will be updated to reflect these
changes as well as to restrict land-uses that fall outside of the assumed development
pattern and are known to increase traffic impacts dramatically, such as drive-through
restaurants and gas stations. The amendment to the mitigation measures responds to
the modified land-use scenario and Master Plan of Development amendment, ensuring
that development within the Specific Plan area does not degrade the interchange to
unacceptable levels. The proposed modification allows for property development to
proceed with construction of identified improvements and modifications to signal timing.
Therefore, no new significant environmental effects or a substantial increase in the
severity of previously identified significant effects has been identified with this analysis
that would result in major changes to the FEIR. The proposed amendments, as has
been shown, lessen the environmental impact resulting from development within the
Specific Plan area.
Is there substantial evidence in the record revealing that there have been substantial
changes with respect to the circumstances under which the project is undertaken
which will require major revisions of the previous EIR due to the involvement of new
significant environmental effects or a substantial increase in the severity of previously
identified significant effects as a result of the MP Annex LLC’s proposed hotel use
within the Specific Plan?
No, there is no evidence suggesting that there have been substantial changes with
respect to the circumstances under which the project is undertaken which will require
major revisions to the previous EIR due to the involvement of new significant impacts or
increases in the severity of previously identified impacts. While the development pattern
and land-use projections within the Specific Plan area are proposed with the
amendments, all uses proposed are allowed or conditionally allowed within the underlying
Commercial Retail (CR) zoning designation. The additional traffic supplemental analysis
reveals that no new significant environmental effects would result from the revisions and
there will be no increase in the severity of any previously identified significant effects. It
has been shown that the proposed amendments will in fact decrease the level of traffic
impact to the Del Rio / 101 interchange as well as the Del Rio / El Camino Real
.
intersection.
Is there substantial evidence in the record revealing that there is new information of
substantial importance related to the proposed amendments, which was not known
and could not have been known with the exercise of reasonable diligence at the time
the previous EIR was certified that shows: (1) the project will have one or more
significant effects not discussed in the EIR, (2) significant effects previously shown
will be substantially more severe that shown in the previous EIR, (3) mitigation
measure or alternatives previously found to be infeasible would in fact be feasible, or
(4) there are considerably different mitigation measure or alternatives from those
analyzed in the previous EIR that would substantially reduce one or more significant
effects?
No, there is no evidence suggesting that there is new information of substantial
importance relating to new significant effects or the severity of previously identified
significant effects, or new alternatives or mitigation measures or the efficacy of previously
considered alternatives or mitigation measures. At the time of the certification of the
previous EIR, traffic impacts and mitigations were identified based on the construction of
a regional retail center on the Annex portion of the Specific Plan area and a Walmart store
on the Major Tenant site. This analysis reveals that no new significant environmental
effects would result from the amendments as proposed, and in fact there will be a
decrease in the severity of previously identified impacts. As a consequence of this
conclusion, it can be concluded that no new mitigation measures or alternatives need be
analyzed.
3.0 BASIS FOR DECISION TO PREPARE AN ADDENDUM
CEQA Guidelines Section 15164 explains when an addendum to an EIR is required:
(a) The lead agency or a responsible agency shall prepare an addendum to a
previously certified EIR if some changes or additions are necessary but none
of the conditions described in Section 15162 calling for preparation of a
subsequent EIR have occurred.
(b) An addendum to an adopted negative declaration may be prepared if only
minor technical changes or additions are necessary or none of the conditions
described in Section 15162 calling for the preparation of a subsequent EIR
or negative declaration have occurred.
(c) An addendum need not be circulated for public review but can be included
in or attached to the final EIR or adopted negative declaration.
(d) The decision-making body shall consider the addendum with the final
EIR or adopted negative declaration prior to making a decision on the
project.
(e) A brief explanation of the decision not to prepare a subsequent EIR pursuant
to Section 15162 should be included in an addendum to an EIR, the lead
agency's required findings on the project, or elsewhere in the record. The
.
explanation must be supported by substantial evidence.
Although the project description has been refined in response to changes in the
retail sector and the major tenant’s (Walmart) decision to cancel development plans
in Atascadero, an addendum is appropriate because impacts have been shown to
decrease from the previously certified FEIR and because none of the conditions
described in Section 15162 calling for preparation of a subsequent EIR have
occurred.
More specifically, the project will reduce the level of anticipated traffic intensive
development, therefore reducing overall and peak hour vehicle trips. These
occurrences do not constitute substantial changes to the project or the
circumstances due to the involvement of new significant environmental effects or a
substantial increase in the severity of previously identified significant effects.
Similarly, neither subsequent considerations nor statutory changes constitute new
information that would show new effects or substantially more severe effects.
Likewise, there are no known mitigation measures that would in fact be infeasible
or that the project proponents have declined to implement. Furthermore, there have
been no other changes, evidence or new information which would require revisions
to the previous EIR. Because none of the criterion in section 15162 has been met,
an addendum is appropriate.
Attachments:
Attachment 1: Redlined Mitigation Measures and Monitoring Program
Attachment 2: 2020 Refined Traffic Analysis and Mitigation Identification
.
PC Resolution
Exhibit A, Attachment 1
Redlined Mitigation Monitoring and Reporting Program
for the
2020 Addendum to the FINAL
Environmental Impact Report
Del Rio Road Commercial Area Specific Plan
City of Atascadero, San Luis Obispo County, California
State Clearinghouse No. 2010051034
The attached Mitigation Monitoring Program excepts represent measures modified for
the 2020 Specific plan Update. The full Mitigation Monitoring Program is on file at the
City of Atascadero.
.
City of Atascadero - Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Michael Brandman Associates
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Table 1: Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Mitigation Measures Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
MM AIR-2f: Prior to issuance of the first certificate of
occupancy for the first commercial building, the project applicant
shall submit a Transportation Demand Management (TDM)
Program to the City of Atascadero for review and approval. The
TDM program shall be prepared by a qualified transportation
consultant/engineer and identify TDM measures for the Walmart
and Annex commercial uses. The TDM program shall contain
the following provisions:
• The TDM program shall establish a goal of reducing AM peak
hour, PM peak hour, and Saturday midday peak hour trips
associated with employee travel by a minimum of 10 percent.
• The TDM program shall be reviewed annually (or more
frequently if needed) to determine that it reflects the needs and
priorities of project tenants and their employees. Changes
shall be made on an as needed basis in order to ensure that the
TDM program can readily attain the 10 percent reduction goal.
• The TDM program may include, but not be limited to, the
following measures:
- Employer-sponsored vanpooling or carpooling, which
may also involve provision of vehicles, staffed-ride
matching services, and guaranteed ride home programs
to increase participation.
- Incentives for non-single-occupant vehicle commute
Approval of TDM
Program
Prior to issuance of
the first certificate
of occupancy for
the first
commercial
building
City of Atascadero
.
City of Atascadero - Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Michael Brandman Associates
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Table 1 (cont.): Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Mitigation Measures Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
trips (i.e., carpooling/vanpooling, transit, bicycling,
walking, etc.)
- Flex time scheduling to avoid peak hour travel
- Staggered work hours to avoid peak hour travel
- Compressed work schedules to avoid peak hour travel
- End of trip facilities such as lockers, showers, or storage
facilities, as coordinated with Mitigation Measure
TRANS-6f.
- Provision of kiosks that provide information about the
TDM program.
6. Hazards and Hazardous Materials
MM HAZ-1a: Prior to issuance of grading permits on the South-East
project site (formerly the Walmart site) in areas where THP-D has
been detected, the applicant shall conduct soil sampling using a
Hollow Stem Auger to delineate the horizontal and vertical extent of
the TPH-D in order to implement a soil remediation program. Soil
remediation shall be conducted in accordance with California
Department of Toxic Substances Control (DTSC) guidelines.
Contaminated soil shall be excavated and disposed of at an approved
disposal facility. Following excavation, confirmation sampling shall
be conducted to confirm whether remaining soil meets acceptable
applicable regulatory levels. The excavation shall be backfilled with
clean soil. The soil remediation activities shall be completed prior to
issuance of building permits. The applicant shall submit
documentation to the City of Atascadero demonstrating that soil
testing was performed and any necessary remediation was completed
Submittal of
documentation
Prior to issuance of
grading permits on
the Walmart site in
areas where THP-
D has been
detected
City of Atascadero
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City of Atascadero - Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Michael Brandman Associates
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Table 1 (cont.): Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Mitigation Measures Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
as part of the grading permit application.
MM HYD-3a: Prior to commencement of grading activities, the
property owner shall consult with the Central Coast Regional
Water Quality Control Board regarding further actions with the
groundwater plume on the South-East project site (formerly the
Walmart site). Consultation shall consist of determining whether (1)
further monitoring or remediation is necessary or (2) no further
actions are necessary. If the Regional Water Quality Control Board
determines that further monitoring or remediation is necessary, the
project applicant shall incorporate provisions for such activities into
the project plans and submit them, as necessary, to the agency for
review and approval. If the Regional Water Quality Control
Board determines that no further action is necessary, the
groundwater monitoring wells may be removed with Central
Coast Regional Water Quality Control Board approval.
Completion of
consultation; submittal
of documentation
Prior to
commencement of
grading activities
for the Walmart
site
City of Atascadero;
Central Coast
Regional Water
Quality Control
Board
.
City of Atascadero - Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Michael Brandman Associates
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Table 1 (cont.): Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Mitigation Measures Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
MM NOI-4b: Prior to issuance of building permits for the
North End project site (Formerly the Annex project), the project
applicant shall prepare and submit plans to the City of Atascadero
depicting minimum 3-foot-high parapet walls on the perimeter of all
rooftops that have rooftop mechanical equipment.
Approval of plans
Prior to issuance of
building permits
for the Annex
project
City of Atascadero
MM NOI-4c: Prior to issuance of building permits for the North end
project site Annex project, the project applicant shall prepare and
submit plans to the City of Atascadero depicting two minimum 6-
foot-high walls: one along the portion of the shared property line of
the Annex areacommercial development and the residence
represented by Receiver 1 (east of El Camino Real and north of
Annex areathe commercial development), and the other along the
portion of the shared property line of the Annexcommercial
development area and the residence represented by Receiver 15 (west
of El Camino Real and south of Annex arethe commercial
development sitea). The length of both walls shall cover the area that
is within 100 feet of the offsite residential structure. Since both
residences are existing nonconforming uses, if either structure is no
longer being used for residential or other sensitive receptor purposes
at the time building permits are obtained, then the associated wall(s)
shall not be constructed. The walls shall be of high-quality, wood-
fence design and incorporate graffiti resistance measures (e.g.,
landscaping). The approved plans shall be incorporated into the
project.
Approval of plans Prior to issuance of
building permits
for the Annex
project
City of Atascadero
.
City of Atascadero - Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Michael Brandman Associates
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Table 1 (cont.): Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Mitigation Measures Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
MM NOI-4d: Prior to issuance of building permits for the
North-End project’s eastern site Annex project, the project applicant
shall prepare and submit plans to the City of Atascadero depicting a
minimum 8-foot-high sound wallappropriate sound mitigation along
the eastern edge of the truck loading docks for Pads B and C on the
Annex portion the commercial area of the project area adjacent to
existing residential uses. The wall sound mitigation may consist of
walls, landscaping, and/or other constructionmethods and shallshall
be of high-quality design and incorporate graffiti resistance measures
(e.g., landscaping). The approved plans shall be incorporated into the
project.
Approval of plans Prior to issuance of
building permits
for the Annex
project
City of Atascadero
MM NOI-4f: Prior to issuance of building permits for the
South-East project site Walmart project, the project applicant shall
prepare and submit plans to the City of Atascadero depicting a
minimum a 4-foot-high sound walla sound barrier around the
proposed Walmart trash compactor trash receptacles, loading docks
and any other potential noise sourcespad to attenuate noise. The
wallAny sounds walls shall be of high-quality design and incorporate
graffiti resistance measures (e.g., landscaping). The approved plans
shall be incorporated into the project.
Approval of plans Prior to issuance of
building permits
for the Walmart
project
City of Atascadero
MM NOI-6: Prior to the final discretionary approval for the
South-East project site component multiple-family residential
unitscomponent, the project applicant shall retain a qualified
acoustical consultant to evaluate potential noise impacts on the
dwelling units. The analysis shall assess potential noise impacts to the
proposed multiple-family residential units from both nearby
transportation and stationary sources and, if required, provide
mitigation to reduce the noise levels to within the City standards.
Mitigation may include but is not limited to the installation of noise
barriers, Sound Transmission Class-rated windows and door
assemblies, building placement or implementation of other
appropriate noise-reducing measures. The project plans shall reflect
the noise attenuation recommendations from the noise evaluation, as
necessary.
Approval of plans Prior to the final
discretionary
approval for the
Walmart
component
multiple-family
residential units
City of Atascadero
.
City of Atascadero - Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Michael Brandman Associates
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Table 1 (cont.): Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Mitigation Measures Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
11. Transportation
MM TRANS-la: Prior to issuance of building permits for each
use, the project applicants shall provide the City of Atascadero
with all applicable traffic impact fees for their proportional-share
impact on TIF funded Circulation System Facilities other than
the Del Rio Road/US 101 interchange, which is subject to a
separate TIF payment described in Mitigation Measures TRANS-
1d 1c and TRANS-1e1d. The traffic impact fees for all uses shall be
subject to the City's latest adopted fee schedule., with the
exception of the Walmart Superstore, which will pay
$11.14/square foot in accordance with the proportional-share
methodology prepared by RCS, based on the ITE land-use rate
for "Free Standing Discount Superstores."
Receipt of fees Prior to issuance of
building permits
for each use
City of Atascadero
MM TRANS-lb: Prior to issuance of the final certificate of
occupancy for a high traffic generating use (exceeding 4,963 total
daily trips or 277 weekday p.m. peak hour trips) at the South-East
project siteWalmart, the intersection of El Camino Real/San Anselmo
Road (North) shall be improved with a signal. Should a developer
construct the improvements, any costs of the installed improvements
in excess of the project’s proportional share, may be eligible for a TIF
fee credit. Any potential TIF fee credit will be calculated by the City
and will comply with any City resolution guiding TIF Fee credits in
place at the time of construction of the improvements. The project
applicant shall install the signal. The City of Atascadero shall
determine the financial obligation of the applicant for the cost of the
improvement, and the applicant installing the improvement shall be
eligible for a fee credit for the cost of these improvements in excess
of the project's proportional-share contribution.
Site inspection;
acceptance of
improvements
Prior to issuance of
the final certificate
of occupancy for
Walmart
City of Atascadero
.
City of Atascadero - Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Michael Brandman Associates
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Table 1 (cont.): Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Mitigation Measures Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
MM TRANS-lc: Prior to issuance of the final certificate of
occupancy for Walmart, the project applicant shall convert the
intersection of Del Rio Road/El Camino Drive to a modern
roundabout. The roundabout shall provide an inscribed diameter
of a minimum of 160 feet and a combination of single and dual
circulating lanes. Single-lane approaches shall be adequate on
the southbound and westbound entrances. The northbound
approach shall include a dual-lane entry with a left-only lane and
a shared through/right-turn lane. The eastbound approach shall
include a shared through/left-turn lane and a minimum 125-foot-
long, right-turn lane. The City of Atascadero shall determine the
financial obligation of the applicant for the cost of the
improvement, and the applicant installing the improvement shall
be eligible for a fee credit for the cost of these improvements in
excess of the project's proportional-share contribution.
MM TRANS-lc: Prior to occupancy of the first new building within the
Specific Plan on the east side of El Camino Real, modifications to the
traffic signal at Del Rio Road/El Camino Real shall be completed by the
developer to more efficiently orchestrate the movement of conflicting
traffic. This modification requires the replacement of the northbound
left-turn protected phasing (green arrow) with protected-permissive
phasing (green arrow that goes to green ball or flashing yellow arrow),
and the southbound left-turn protected phasing with permissive phasing
(green ball or flashing yellow arrow). The eastbound and westbound
phases, which currently activate at the same time, shall be split to operate
sequentially, or one direction and then the other. These changes shall
require modification to the existing signal infrastructure to incorporate
updated signal heads. In addition, this mitigation includes adjustment to
the signal phasing in terms of recalls, phase lengths, and the overall cycle
length.
Site inspection;
acceptance of
improvements
Prior to issuance of
the final certificate
of occupancy for
Walmart
City of Atascadero
.
City of Atascadero - Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Michael Brandman Associates
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Table 1 (cont.): Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Mitigation Measures Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
MM TRANS-ld: Prior to issuance of each building permit for
the project, the project applicant shall provide the City of
Atascadero with proportional-share fees for the conversion of the
intersection of Del Rio Road/US 101 Northbound Ramps to a
single-lane modern roundabout with a minimum 150-foot-long,
right-turn bypass lane on the westbound approach. The traffic
impact fee shall be based on the size of the building subject to
the building permit and shall be consistent with the proportional
share methodology prepared by RCS as described in the "TIF
Collection Process" discussion in Section 3.11, Transportation.
The City of Atascadero shall collect the fees and shall be
responsible for constructing the roundabout improvements.
Implementation of the northbound and southbound roundabouts
shall occur in tandem. The roundabout shall be in place no later
than the issuance of the first certificate of occupancy for the
Annex commercial uses.
MM TRANS 1-d
Prior to occupancy of the first use that exceeds 134 p.m. cumulative
peak hour trips, a westbound right-turn lane shall be added to the
intersection of Del Rio Road/US 101, such that there would be two
westbound lanes on Del Rio Road from El Camino Real to the US 101
North ramp. This would require widening Del Rio Road, the
construction of a retaining wall on the north side of Del Rio Road, and
reconstruction of the curb return.
Concurrent with the addition of the right turn lane noted above, the
intersection of Del Rio Road/El Camino Real shall be reconfigured at
the eastbound approach from through/left-turn and right-turn lanes, to
left-turn lane and through/right-turn lanes, moving the through
movement from the left lane to the right lane. This includes widening
the eastbound departure (on the east leg of the intersection) to avoid
excessive lateral shifting of through traffic. With a dedicated
eastbound left-turn lane, the eastbound-westbound split phasing shall
be required to be replaced with concurrent timing, as well as
protected-permissive phasing for the eastbound left-turn movement.
With protected left-turn phasing in the eastbound direction and a
prohibition of eastbound U-turns, a southbound right-turn overlap
shall be provided, which is a green arrow that enables southbound
right-turning drivers to continue without stopping concurrently with
Receipt of fees / Site
inspection;
acceptance of
improvements
Prior to issuance of
each building permit
for the project
City of Atascadero
.
City of Atascadero - Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Michael Brandman Associates
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Table 1 (cont.): Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Mitigation Measures Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
the eastbound left-turn movement. Additionally, the signal at Del Rio
Road/El Camino Real shall be coordinated with the signals at Del Rio
Road/US 101 North Ramps and Del Rio Road/US 101 South Ramps.
This will require extending the interconnect hardware between the ramp
signals to Del Rio Road/El Camino Real, and potentially upgrading the
signal hardware at Del Rio Road/El Camino Real to be compatible with
interconnect technology if it is not already.
All development within the Specific Plan area shall be responsible for
paying their fair share towards these improvements as a special impact
fee. The special impact fee will be in addition to the Citywide impact
fees in place at the time of development and shall be collected prior to
issuance of any permit. Should a developer construct the improvements,
any costs of the installed improvements in excess of the project’s
proportional share, may be eligible for a TIF fee credit. Any potential
TIF fee credit will be calculated by the City and will comply with any
City resolution guiding TIF Fee credits in place at the time of
construction of the improvements. The developer constructing the
improvements may also be eligible for reimbursement from other
development within the Specific Plan area should improvements be
installed prior to Specific Plan build-out.
MM TRANS-le: Prior to issuance of each building permit for
the project, the project applicant shall provide the City of
Atascadero with proportional-share fees for the construction of a
five-legged, single-lane modern roundabout at the intersection of
Del Rio Road/US 101 Southbound Ramps that incorporates
Ramona Road as the fifth approach. The traffic impact fee shall be
based on the size of the building subject to the building permit
and shall be consistent with the proportional share cost
methodology prepared by RCS as described in the "TIF
Collection Process" discussion in Section 3.11, Transportation.
The City of Atascadero shall collect the fees and shall be
responsible for constructing the roundabout improvements.
Implementation of the northbound and southbound roundabouts
shall occur in tandem. The roundabout shall be in place no later
than the issuance of the first certificate of occupancy for the
Annex commercial uses.
Receipt of fees Site
inspection;
acceptance of
improvements
Prior to issuance of
each building
permit
City of Atascadero
.
City of Atascadero - Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Michael Brandman Associates
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Table 1 (cont.): Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Mitigation Measures Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
Prior to issuance of building permits for any land use that exceeds 293
cumulative weekday p.m. peak hour trips within the Specific Plan area,
the following improvements shall be completed:
Widening the eastbound approach to Del Rio Road/El Camino
Real to three lanes that extend upstream to Del Rio Road/US
101 North Ramps, with one lane each assigned to left turns,
through lanes, and right turns.
The westbound approach shall be widened to include a right-
turn pocket.
A second northbound left-turn lane shall be constructed to
accommodate traffic leaving the commercial developments and
heading toward the freeway.
Overlaps shall be added to further improve traffic flow.
The Del Rio Road overpass shall to be widened to four lanes,
with a through/left-turn combined lane and through lane
approaching eastbound to Del Rio Road/US 101 North Ramps
and left-turn and through/left-turn combined lanes on the
westbound approach to Del Rio Road/US 101 South Ramps.
At Del Rio Road/US 101 South Ramps, the southbound
approach shall be expanded to include an additional left-turn
lane, and the phasing shall be modified to split the eastbound
and westbound approaches.
Interconnect shall be provided between all three signals to
coordinate cycles.
Should a developer construct the improvements, any costs of the
installed improvements in excess of the project’s proportional share, may
be eligible for a TIF fee credit. Any potential TIF fee credit will be
calculated by the City and will comply with any City resolution guiding
TIF Fee credits in place at the time of construction of the
improvements. The developer constructing the improvements may also
be eligible for reimbursement from other development within the
Specific Plan area should improvements be installed prior to Specific
Plan build-out.
MM TRANS-4: Prior to recordation of the final map for the
South-East project siteWalmart component, the project applicant shall
revise the improvement plans to provide for a northbound left-turn
lane on El Camino Real at the new intersection serving the Walmart
site. The City shall review and approve the lane geometry.
Approval of plan Prior to recordation
of the final map for
the Walmart
component
City of Atascadero
.
City of Atascadero - Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Michael Brandman Associates
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Table 1 (cont.): Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Mitigation Measures Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
MM TRANS-6a: Prior to approval of the final map for the
Walmart and Annexeither site components, the applicant shall
identify suitable locations for one or more bus stops as required by
the City of Atascadero. Such stops may be located along street
frontages or within the project site. The applicant shall consult with
the Regional Transit Authority, Atascadero Transit, and the City of
Atascadero about suitable locations and amenities. The bus stops
identified for each site shall be installed and available for service
prior to opening day of each project component.
Approval of plan; site
inspection
Prior to issuance of
the final certificate
of occupancy for
Walmart
City of Atascadero
MM TRANS-6b: Prior to issuance of the final certificate of
occupancy for the commercial uses, the applicant shall install bicycle
facilities (racks or lockers) in convenient locations. Bicycle storage
shall be provided at a ratio of no less than 1 bicycle space for each 20
vehicular spaces.
Site inspection Prior to issuance of
the final certificate
of occupancy for
the Walmart and
Annex nonresidential
uses
City of Atascadero
MM TRANS-6c: Prior to issuance of building permits for the
future multi-family residential uses on the Walmart South -East
development site, the applicant shall demonstrate that each dwelling
unit provides enclosed space suitable for storage of at least two
bicycles. Such enclosed space may consist of garages, storage rooms,
closets, or other non-living area spaces that allow the occupant(s) to
securely store a bicycle and avoid exposure to theft or adverse
weather conditions.
Approval of plans Prior to issuance of
building permits
for the future
multi-family
residential uses on
the Walmart site
City of Atascadero
MM TRANS-6d: Prior to acceptance of improvements to El
Camino Real and Del Rio Road, the City of Atascadero shall
verify that project frontage improvements on El Camino Real
include Class II bicycle lanesaccommodate bicycle travel and that
bicycle loop detectors have been installed as a component oftravel
will be a consideration at the signal installation at El Camino
Real/Proposed Public Street.
Site inspection;
acceptance of
improvements
Prior to acceptance
of improvements to
El Camino Real
and Del Rio Road
City of Atascadero
.
City of Atascadero - Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Michael Brandman Associates
H:\Client (PN-JN)\3622\36220003\3 - Final EIR\MMRP\33620003 Del Rio Road MMRP.doc
12
Table 1 (cont.): Del Rio Road Commercial Area Specific Plan Mitigation Monitoring and Reporting Program
Mitigation Measures Method of Verification
Timing of
Verification
Responsible for
Verification
Verification of Completion
Date Initial
MM TRANS-6e: Prior to issuance of building permits for theany
Walmart and Annex commercial buildings, the project applicant shall
prepare and submit plans to the City of Atascadero for review and
approval that demonstrate the provision of pedestrian facilities. Such
facilities shall consist of sidewalks along the frontages with El
Camino Real, Del Rio Road, and the new access road serving the
Walmart sSouth -eEast development site, and direct pedestrian
connections between parking fields and building entrances. The
former WalmartSouth-East project site shall provide a pedestrian
connection from the store entrancethe front of commercial buildings
at the front of the building to Del Rio Road that generally parallels
the a driveway connection to Del Rio Road. Pavement treatments or
similar features shall be installed at locations where pedestrian
facilities cross drive aisles. All pedestrian facilities shall comply with
the applicable requirements of the Americans With Disabilities Act.
Approval of plans Prior to issuance of
building permits
for the Walmart
and Annex
commercial
buildings
City of Atascadero
MM TRANS-6f: Prior to acceptance of improvements to El
Camino Real, Del Rio Road, and the new public street serving the
South-East Walmart development site, the City of Atascadero shall
verify that crosswalk markings have been installed across all
driveway access points leading to and from the project sites where
sidewalks are constructed. Additionally, high visibility markings shall
be installed across the southern driveway from "Proposed Public
Street."
Site inspection;
acceptance of
improvements
Prior to acceptance
of improvements to
El Camino Real,
Del Rio Road, and
the new public
street serving
Walmart
City of Atascadero
MM TRANS-7b: If improvements to During the closure of the US
101/Del Rio Road interchange have significant impacts to the
interchange operations, , the City of Atascadero shall station trained
traffic control officers at the intersection of San Anselmo Road/US
101 Northbound Ramps shall be monitored during the peak hours to
facilitate acceptable queuing operations
Monitoring During closure of
the US 101/Del
Rio Road
interchange
City of Atascadero
MM TRANS-7c: If improvements to During closure of the US
101/Del Rio Road interchange have significant impacts to the
interchange operations, , the City of Atascadero shall station trained
traffic control officers at the intersection of San Anselmo Road/US
101 Southbound Ramps shall be monitored during the peak hours to
facilitate acceptable queuing operations.
Monitoring During closure of
the US 101/Del
Rio Road
interchange
City of Atascadero
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Traffic Analysis for the Del Rio Specific Plan Amendment Traffic Analysis
August 26, 2020
Executive Summary
The Del Rio Road interchange with US 101 through to El Camino Real was evaluated against a variety of land use
development scenarios in the Del Rio Specific Plan area to determine how the added traffic would affect delays
and queues throughout the interchange under Existing and Future Conditions. The Amended Specific Plan
scenario was developed as a likely mixture of land uses to be represented in an Amended Specific Plan for the
area. The Amended Specific Plan Plus Regional Shopping scenario was developed based on the Amended Specific
Plan scenario, but with a regional shopping center in place of several other potential developments.
Existing Conditions were assessed based on data collected in March 2018 and it was determined that all study
intersections are operating acceptably at Level of Service (LOS) C or better. The only unacceptable queue lengths
identified are between the intersections of Del Rio Road/US 101 South Ramps and Del Rio Road/Ramona Road,
where only 35 feet of stacking distance is available.
Future (2035) Conditions were developed from San Luis Obispo Council of Governments (SLOCOG) model data,
with trips anticipated to be generated by several potential developments around the interchange added to the
model volumes. It was also assumed that a southbound right-turn lane would be added at Del Rio Road/El Camino
Real, and that Del Rio Road/Ramona Road would be reconstructed to provide 240 feet of stacking to and from the
Del Rio Road/US 101 South Ramps intersection. With these Future Conditions applied, all queue lengths would
be acceptable except for a slight overage in the northbound left-turn lane at Del Rio Road/El Camino Real. For
operations, this intersection would operate at LOS E during the p.m. peak hour while the other intersections would
continue to operate at LOS C or better.
The trip generation for the Amended Specific Plan scenario is estimated at 4,963 trips per day, including 208 during
the a.m. peak hour and 277 during the p.m. peak hour. With these volumes applied to the Future Conditions
scenario, the intersection of Del Rio Road/El Camino Real would operate at LOS F and with unacceptable queues
in the northbound left-turn lane and on the eastbound approach. Several mitigations were tested, but only
extensive modifications to the signal at Del Rio Road/El Camino Real would improve queues and delays to an
acceptable level.
For the Amended Specific Plan Plus Regional Shopping scenario, the trip generation is estimated at 9,383 trips per
day, including 331 morning peak hour trips and 743 afternoon peak hour trips. When these trips are added to the
Future Conditions scenario, all intersections except for Del Rio Road/Ramona Road would experience
unacceptable queues and delays. Although several less-intensive mitigations were assessed, extensive
interchange widening would be needed to achieve acceptable queues and delays. This includes two southbound
left-turn lanes at Del Rio Road/US 101 South Ramps, four lanes across the Del Rio Road overpass, an added
westbound right-turn lane to Del Rio Road/US 101 North Ramps, added eastbound, northbound, and westbound
lanes approaching Del Rio Road/El Camino Real, and several signal modifications throughout the corridor. As an
alternative, a series of roundabouts would result in acceptable operations while maintaining the existing overpass
structure.
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Traffic Analysis for the Del Rio Interchange
August 26, 2020
Introduction
This traffic analysis for the Del Rio Specific Plan Amendment presents an analysis of the potential traffic impacts
associated with the various proposed development alternatives in the vicinity of the Del Rio Road interchange
with US 101 in the City of Atascadero. The traffic study was completed in accordance with the criteria established
by the City of Atascadero and is consistent with standard traffic engineering techniques.
Prelude
The purpose of this traffic analysis is to provide City staff and policy makers with data they can use to make an
informed decision regarding the potential traffic impacts of proposed land use development, and any associated
improvements that would be required to mitigate these impacts to a level of insignificance as defined by the City’s
General Plan or other policies. Adverse effects on vehicular traffic are typically evaluated by determining the
number of new trips that the proposed use would be expected to generate, distributing these trips to the
surrounding street system based on existing travel patterns or anticipated travel patterns specific to the proposed
scenario, then analyzing the impact the new traffic would be expected to have on critical intersections or roadway
segments.
Analysis Profile
The Del Rio Road Specific Plan Amendment analysis includes four intersections and four development sites in the
vicinity of the Del Rio Road interchange, as shown in Figure 1.
.
Traffic Analysis for the Del Rio Interchange
ata031-3.ai 6/20
Not to Scale
1
2
34
Church
Property Annex
West
Annex
East
Wal-Mart Site
Figure 1 – Vicinity Map
Study Intersection
LEGEND
Intersection 1
Intersection 2
Intersection 3 Intersection 4
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Traffic Analysis for the Del Rio Interchange
August 26, 2020
Transportation Setting
Operational Analysis
Study Area and Periods
The study area consists of the following intersections:
1. Del Rio Road/El Camino Real
2. Del Rio Road/US 101 N Ramps
3. Del Rio Road/US 101 S Ramps
4. Del Rio Road/Ramona Road
Operating conditions during the weekday p.m. peak period were evaluated as this time period reflects the highest
traffic volumes areawide and for the potential developments. The evening peak hour occurs between 4:00 and
6:00 p.m. and typically reflects the highest level of congestion of the day during the homeward bound commute.
Study Intersections
Del Rio Road/El Camino Real is a signalized intersection with two approach lanes in the northbound direction
and one approach lane in the other three directions. There are crosswalks on all four legs, protected left-turn
phasing on El Camino Real, and permissive left-turn phasing on Del Rio Road. A bicycle lane is provided on the
south leg.
Del Rio Road/US 101 North Ramps is a four-legged intersection with three approaches as the US 101 North on-
ramp is one-way in the northbound direction. Each of the three approaches has one lane and there is a crosswalk
on the south leg. The eastbound approach has protected-permissive left-turn phasing and the signal is
coordinated with the traffic signal at Del Rio Road/US 101 South Ramps.
Del Rio Road/US 101 South Ramps is a signalized intersection that is coordinated with Del Rio Road/US 101
North Ramps and has protected-permissive left-turn phasing in the westbound direction. The US 101 South on-
ramp is one-way in the southbound direction, and the other three approaches have one lane each. There is a
crosswalk on the south leg.
Del Rio Road/Ramona Road is a tee intersection with stop controls on Ramona Road only. There is one approach
lane in each direction.
The locations of the study intersections and the existing lane configurations and controls are shown in Figure 1.
Specific Plan Land Use
The Specific Plan study area consists of the following underdeveloped lots that will potentially be developed in
the future:
1. Annex West: Lot in the northwest quadrant of the Del Rio Road/El Camino Real intersection;
2. Annex East: Lot in the northeast quadrant of the Del Rio Road/El Camino Real intersection;
3. Walmart Site: Lot in the southeast quadrant of the Del Rio Road/El Camino Real intersection that was slated
to be developed into a Walmart store; and
4. Church Property: Lot north of Del Rio Road and to the west of US 101.
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Traffic Analysis for the Del Rio Specific Plan Amendment Traffic Analysis
August 26, 2020
Traffic Operational Analysis
Intersection Level of Service Methodologies
Level of Service (LOS) is used to rank traffic operation on various types of facilities based on traffic volumes and
roadway capacity using a series of letter designations ranging from A to F. Generally, Le vel of Service A represents
free flow conditions and Level of Service F represents forced flow or breakdown conditions. A unit of measure
that indicates a level of delay generally accompanies the LOS designation.
The study intersections were analyzed using methodologies published in the Highway Capacity Manual (HCM),
Transportation Research Board, 2010. This source contains methodologies for various types of intersection
control, all of which are related to a measurement of delay in average number of seconds per vehicle.
The Levels of Service for the intersection with side street stop controls, Del Rio Road/Ramona Road, was analyzed
using the “Two-Way Stop-Controlled” intersection capacity method from the HCM. This methodology determines
a level of service for each minor turning movement by estimating the level of average delay in seconds per vehicle.
Results are presented for individual movements together with the weighted overall average delay for the
intersection.
The remaining study intersections are controlled by traffic signals and were evaluated using the signalized
methodology from the HCM. This methodology is based on factors including traffic volumes, green time for each
movement, phasing, whether the signals are coordinated or not, truck traffic, and pedestrian activity. Average
stopped delay per vehicle in seconds is used as the basis for evaluation in this LOS methodology. For purposes of
this study, delays were calculated using signal timing obtained from Caltrans and the City of Atascadero.
The ranges of delay associated with the various levels of service are indicated in Table 1.
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Traffic Analysis for the Del Rio Interchange
August 26, 2020
Table 1 – Intersection Level of Service Criteria
LOS Two-Way Stop-Controlled Signalized
A Delay of 0 to 10 seconds. Gaps in traffic are readily
available for drivers exiting the minor street.
Delay of 0 to 10 seconds. Most vehicles arrive
during the green phase, so do not stop at all.
B Delay of 10 to 15 seconds. Gaps in traffic are
somewhat less readily available than with LOS A, but
no queuing occurs on the minor street.
Delay of 10 to 20 seconds. More vehicles stop than
with LOS A, but many drivers still do not have to
stop.
C Delay of 15 to 25 seconds. Acceptable gaps in traffic
are less frequent, and drivers may approach while
another vehicle is already waiting to exit the side
street.
Delay of 20 to 35 seconds. The number of vehicles
stopping is significant, although many still pass
through without stopping.
D Delay of 25 to 35 seconds. There are fewer acceptable
gaps in traffic, and drivers may enter a queue of one or
two vehicles on the side street.
Delay of 35 to 55 seconds. The influence of
congestion is noticeable, and most vehicles have to
stop.
E Delay of 35 to 50 seconds. Few acceptable gaps in
traffic are available, and longer queues may form on
the side street.
Delay of 55 to 80 seconds. Most, if not all, vehicles
must stop and drivers consider the delay excessive.
F Delay of more than 50 seconds. Drivers may wait for
long periods before there is an acceptable gap in
traffic for exiting the side streets, creating long queues.
Delay of more than 80 seconds. Vehicles may wait
through more than one cycle to clear the
intersection.
Reference: Highway Capacity Manual, Transportation Research Board, 2010
Analysis of Interchange Area Queuing
Adverse queuing conditions can result in traffic impacts at closely spaced intersections, particularly at freeway
interchanges where queues can potentially affect mainline freeway operation. For these reasons, an analysis of
queuing was performed for the Del Rio Road corridor between the US 101 South Ramps intersection and El Camino
Real Road, including the intersection of US 101 North Ramps. The analysis was focused on the weekday p.m. peak
hour as this time period has the highest delays and traffic volumes, as well as the greatest potential for queuing
impacts to occur.
The projected vehicle queues were determined using the applied timing schemes in SIMTRAFFIC, which is a traffic
simulation extension of SYNCHRO. SIMTRAFFIC generates random “seeding” of vehicles on the street network
and then simulates how vehicles will flow through the system using the actual volumes, phasing, and timing
developed in SYNCHRO. Because each SIMTRAFFIC run is unique, a series of five separate “runs” was used to
develop queuing estimates. The maximum queues projected for each lane in the five SIMTRAFFIC runs were
averaged and are reported as the maximum queue.
Traffic Operation Standards
Caltrans indicates that they endeavor to maintain operation at the transition from LOS C to LOS D, per their Guide
for the Preparation of Traffic Impact Studies, 2002. Where intersections are integral to a local jurisdictions
transportation system, Caltrans often accepts the operational standard applied by the local agency, in this case,
the City of Atascadero.
The City of Atascadero’s General Plan, July 2016, established the City’s threshold for acceptable operation as LOS
C or better.
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Traffic Analysis for the Del Rio Specific Plan Amendment Traffic Analysis
August 26, 2020
Three vehicle queuing operational standards were applied based on industry standard practice regarding safety,
for turn pockets, intersection spacing, and off-ramps. For turn pockets at intersections, the standard applied is to
keep the back of queue within the available stacking space to avoid blocking the through lane. Another standard
is to avoid queue lengths that extend to an upstream intersection, which could block that intersection and create
gridlock. This is especially important for this analysis as the study intersections are in close proximity, with only
240 feet separating intersections on Del Rio Road at El Camino Real and US 101 North Ramps, 290 feet between
US 101 North Ramps and US 101 South Ramps, and 35 feet between US 101 South Ramps and Ramona Road. The
third queuing standard applies to the off-ramp queue lengths which must be maintained at less than the distance
between the stop bar and the gore point of the off-ramp, to avoid spillbacks onto the freeway mainline including
room for deceleration between the gore point and the back of queue.
Existing Conditions
The Existing Conditions scenario provides an evaluation of current operation based on existing traffic volumes
during the p.m. peak period. This condition does not include development-generated traffic volumes. Volume
data was collected in March 2018 while local schools were in session.
All four study intersections operate acceptably as shown in Table 2. The operational analysis worksheets are
included in Appendix A.
Table 2 – Existing PM Peak Hour Intersection Delay
Study Intersection
Approach
Delay (LOS)
1. Del Rio Rd/El Camino Real 23.5 (C)
2. Del Rio Rd/US 101 N Ramps 9.9 (A)
3. Del Rio Rd/US 101 S Ramps 14.9 (B)
4. Del Rio Rd/Ramona Rd 0.7 (A)
Northbound Approach 9.3 (A)
Notes: Delay is measured in average seconds per vehicle; Results
for minor approaches to two-way stop-controlled
intersections are indicated in italics
Future Conditions
The Future Conditions scenario provides an evaluation of estimated Year 2035 traffic volumes during the p.m.
peak period. These conditions include traffic expected to be generated by several anticipated developments
within the land use study area which have been previously approved, but do not include development on the four
sites that are the subject of this analysis.
Derivation of Future Volumes
Segment volumes for the horizon year of 2035 were obtained from the San Luis Obispo Council of Government’s
(SLOCOG’s) gravity demand model and translated to turning movement volumes at each of the study
intersections using the “Furness” method. The Furness method is an iterative process that employs existing turn
movement data, existing link volumes and future link volumes to project likely turning future movement volumes
at intersections.
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Traffic Analysis for the Del Rio Interchange
August 26, 2020
The SLOCOG model data was augmented with the trip generation of several anticipated developments within the
study area. This trip generation was computed using standard rates published by the Institute of Transportation
Engineers (ITE) in Trip Generation Manual, 10th Edition, 2017 for “Gasoline/Service Station with Convenience
Market” (ITE LU 945), “High-Turnover (Sit-Down) Restaurant” (ITE LU 932), “Shopping Center” (ITE LU 820), “Fast-
Food Restaurant with Drive-Through Window ” (ITE LU 934), and “Single-Family Detached Housing” (ITE LU 210).
Some portion of traffic associated with the restaurant uses is drawn from existing traffic on nearby streets. These
vehicle trips are not considered "new," but are instead comprised of drivers who are already driving on the
adjacent street system and choose to make an interim stop and are referred to as “pass-by.” The percentage of
these pass-by trips was developed based on information provided in the Trip Generation Manual. This reference
includes pass-by data collected at numerous locations for many land uses, such as the restaurant use applied in
this traffic analysis. At the developments, pass-by trips would in essence be “captured” from traffic on El Camino
Real.
The expected trip generation of the anticipated developments is indicated in Table 3, with deductions taken for
pass-by trips. These anticipated land uses are expected to generate 3,716 trips per day, including 252 trips during
the a.m. peak hour and 264 trips during the p.m. peak hour. After deductions are taken into account, the scenario
would be expected to generate 3,615 new trips on a daily basis, including 243 during the morning peak hour and
257 during the evening peak hour; these new trips represent the increase in traffic associated with the scenario
compared to existing volumes.
Table 3 – Trip Generation Summary for Anticipated Developments
Land Use Units Daily AM Peak Hour PM Peak Hour
Rate Trips Rate Trips In Out Rate Trips In Out
Del Rio Intersection Area
Gas Station 12 fs 205.36 2,464 12.50 150 77 73 14.00 168 86 82
Sit-Down Restaurant 2 ksf 112.18 224 9.94 20 11 9 9.77 20 12 8
Pass-by -5% -11 -5% -1 -1 0 -5% -1 -1 0
Retail Pad 2 ksf 37.75 76 0.94 2 1 1 3.81 8 4 4
Fast Food w/ Drive Thru 1.9 ksf 470.95 895 40.20 76 39 37 32.7 62 32 30
Pass-by -5% -90 -5% -8 -4 -4 -5% -6 -3 -3
Church Property
Houses 6 du 9.44 57 0.74 4 1 3 0.99 6 4 2
Subtotal 3,716 252 129 123 264 138 126
Reductions -101 -9 -5 -4 -7 -4 -3
Total 3,615 243 124 119 257 134 123
Note: du = dwelling unit; ksf = 1,000 square feet; fs = fuel stations
Future Geometric Changes
As part of the Future Conditions scenario, two key roadway geometric modifications were assumed. The first is
that the intersection of Del Rio Road/Ramona Road would be relocated to the west to provide approximately 240
feet of separation with the intersection of Del Rio Road/US 101 South Ramps. The second modification is the
construction of a southbound right-turn lane at Del Rio Road/El Camino Real, which is assumed to be included
with the development of the Annex West site.
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Traffic Analysis for the Del Rio Specific Plan Amendment Traffic Analysis
August 26, 2020
Operational Analysis
Under the anticipated Future volumes derived from the SLOCOG model and from the above trip generation
analysis, and with the addition of the above geometric changes, the intersection of Del Rio Road/El Camino Real
would operate unacceptably while the remainder of the study intersections would operate acceptably. Future
operating conditions are summarized in Table 4, and LOS worksheets are provided in Appendix A.
Table 4 – Future PM Peak Hour Intersection Delay
Study Intersection
Approach
Delay (LOS)
1. Del Rio Rd/El Camino Real 69.3 (E)
2. Del Rio Rd/US 101 N Ramps 10.6 (B)
3. Del Rio Rd/US 101 S Ramps 19.5 (B)
4. Del Rio Rd/Ramona Rd 1.1 (A)
Northbound Approach 9.6 (A)
Notes: Delay is measured in average seconds per vehicle; Results for minor approaches to two-way stop-controlled
intersections are indicated in italics; Bold text = deficient operation
Buildout of the Amended Specific Plan
The Amended Specific Plan scenario replaces the previously approved Regional Shopping Center on the Walmart
site with a mix of warehousing, light industrial and mixed residential/retail uses.
Trip Generation
The anticipated vehicle trip generation for the proposed land uses was estimated based on standard rates from
the Trip Generation Manual for “Hotel” (ITE LU 310), “High-Turnover (Sit-Down) Restaurant” (ITE LU 932), “Shopping
Center” (ITE LU 820), “Business Park” (ITE LU 770), “Warehousing” (ITE LU 150), and “Multifamily Housing (Low-
Rise)” (ITE LU 220).
Internal Capture Trips
The Trip Generation Manual also includes data and methodologies that can be applied to determine the proportion
of internal trips that may occur within a development area that includes a variety of land uses. Internal trips occur
at mixed-use developments, and in the case of the Walmart Site would consist of residents patronizing adjacent
restaurant and retail uses, as well as employees of nonresidential uses patronizing other nonresidential uses, such
as employees of the business park eating at the restaurant. The majority of these trips would be made by walking,
and the few that would be made by automobile would only travel on-site, so would not affect the adjacent street
network.
Pass-by Trips
As discussed previously, a portion of traffic associated with the restaurant uses would be drawn from existing
traffic on nearby streets. The percentage of these pass-by trips was developed based on information provided in
the Trip Generation Manual and represents trips “captured” from traffic on Del Rio Road or El Camino Real.
Total Scenario Trip Generation
The expected trip generation potential for the proposed uses is indicated in Table 5, with deductions taken for
pass-by and internal capture. The proposed development scenario is expected to generate an average of 5,058
trips per day, including 213 trips during the a.m. peak hour and 285 during the p.m. peak hour. After deductions
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Traffic Analysis for the Del Rio Interchange
August 26, 2020
are taken into account, the development would be expected to generate 4,963 new trips on a daily basis, including
208 during the morning peak hour and 277 during the evening peak hour; these new trips represent the increase
in traffic associated with the scenario compared to existing volumes.
Table 5 – Trip Generation Summary for Amended Specific Plan
Land Use Units Daily AM Peak Hour PM Peak Hour
Rate Trips Rate Trips In Out Rate Trips In Out
Annex West
Hotel 120 rms 8.36 1,003 0.47 56 33 23 0.60 72 37 35
Annex East
Business Park 190 ksf 12.44 2,364 0.40 76 46 30 0.42 80 37 43
Walmart Site
Warehousing 30 ksf 1.74 52 0.17 5 4 1 0.19 6 2 4
Sit-Down Restaurant 2 ksf 112.18 224 9.94 20 11 9 9.77 20 12 8
Pass-by -5% -11 -5% -1 -1 0 -5% -1 -1 0
Mixed Use Retail 15 ksf 37.75 566 0.94 14 9 5 3.81 57 27 30
Mixed Use Residential 10 du 7.32 73 0.46 5 1 4 0.56 6 4 2
Light Industrial 30 ksf 12.44 373 0.40 12 7 5 0.42 13 6 7
Apartments 55 du 7.32 403 0.46 25 6 19 0.56 31 20 11
Internal Capture -5% -84 -5% -4 -2 -2 -5% -7 -4 -3
Subtotal 5,058 213 117 96 285 145 140
Reductions -95 -5 -3 -2 -8 -5 -3
Total 4,963 208 114 94 277 140 137
Note: rms = rooms; du = dwelling unit; ksf = 1,000 square feet
Trip Distribution
The pattern used to allocate new scenario trips to the street network was based on existing traffic patterns. The
applied distribution assumptions and resulting trips are shown in Table 6.
Table 6 – Trip Distribution Assumptions for Amended Specific Plan
Route Percent Daily Trips AM Trips PM Trips
US 101 North of Del Rio Road 35% 1,737 73 97
US 101 South of Del Rio Road 35% 1,737 73 97
El Camino Real South of Del Rio Road 15% 745 32 41
El Camino Real North of Del Rio Road 5% 248 10 14
Del Rio Road West of Ramona Road 5% 248 10 14
Del Rio Road East of El Camino Real 5% 248 10 14
TOTAL 100% 4,963 208 277
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Traffic Analysis for the Del Rio Specific Plan Amendment Traffic Analysis
August 26, 2020
Potential Study Area Mitigations
To assess what mitigations might be required to accommodate the trips that would be generated by the Amended
Specific Plan scenario, four mitigation scenarios were assessed:
Mitigation 1 – This mitigation measure includes the addition of a westbound right-turn lane to the intersection
of Del Rio Road/US 101 North Ramps, such that there would be two westbound lanes on Del Rio Road from El
Camino Real to US 101 North Ramps. This would require widening Del Rio Road, the construction of a retaining
wall on the north side, and reconstruction of the curb return. By splitting westbound traffic into through and
right-turn lanes, the queue length could be reduced by providing drivers two lanes to stack in rather than one for
both movements combined. Additionally, splitting through and right-turning traffic would allow turning drivers
to bypass through drivers who are waiting for a green light, reducing delay and improving operations at Del Rio
Road/US 101 North Ramps.
Mitigation 2 – This mitigation measure would involve several modifications to the traffic signal at Del Rio Road/El
Camino Real to more efficiently orchestrate the movement of conflicting traffic. This modification involves the
replacement of the northbound left-turn protected phasing (green arrow) with protected-permissive phasing
(green arrow that goes to green ball or flashing yellow arrow), and the southbound left-turn protected phasing
with permissive phasing (green ball or flashing yellow arrow). The eastbound and westbound phases, which
currently activate at the same time, would be split to operate sequentially, or one direction and then the other.
These changes would require modification to the existing signal infrastructure to incorporate updated signal
heads. In addition, this mitigation includes adjustment to the signal phasing in terms of recalls, phase lengths,
and the overall cycle length.
Mitigation 3 – This mitigation measure would combine Mitigation 1 and Mitigation 2.
Mitigation 4 – This option includes any modifications that may be required to achieve acceptable operations with
the addition of traffic that would be generated by the Amended Specific Plan scenario. In addition to Mitigation
1 and Mitigation 2 above, the intersection of Del Rio Road/El Camino Real would need to be further modified to
reconfigure the eastbound approach from through/left-turn and right-turn lanes, to left-turn lane and
through/right-turn lanes, essentially moving the through movement from the left lane to the right lane. This may
require widening the eastbound departure (on the east leg of the intersection) to avoid excessive lateral shifting
of through traffic. With a dedicated eastbound left-turn lane, the eastbound-westbound split phasing could be
replaced with concurrent timing, as well as protected-permissive phasing for the eastbound left-turn movement.
With protected left-turn phasing in the eastbound direction and a prohibition of eastbound U-turns, it would be
possible to include a southbound right-turn overlap, which is a green arrow that enables southbound right-
turning drivers to continue without stopping concurrently with the eastbound left-turn movement. Additionally,
the signal at Del Rio Road/El Camino Real would need to be coordinated with the signals at Del Rio Road/US 101
North Ramps and Del Rio Road/US 101 South Ramps. This would require extending the interconnect hardware
between the ramp signals to Del Rio Road/El Camino Real, and potentially upgrading the signal hardware at Del
Rio Road/El Camino Real to be compatible with interconnect technology if it is not already.
Operational Analysis
Upon the addition of scenario-related traffic to the Future volumes, the study intersections are expected to
operate acceptably, except for the intersection of Del Rio Road/El Camino Real, which would operate at LOS F. The
addition of Mitigation 1 (added westbound right-turn lane approaching Del Rio/US 101 North Ramps) would not
mitigate this delay; however, the other three mitigations would result in acceptable operations. These results are
summarized in Table 7. Synchro worksheets are included in Appendix A.
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Traffic Analysis for the Del Rio Interchange
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Table 7 – Future plus Amended Specific Plan PM Peak Hour Intersection Delay
Study Intersection
Approach
Future Future plus Amended Specific Plan
No
Mitigation M1 M2 M3 M4
Delay (LOS)
Delay
(LOS)
Delay
(LOS)
Delay
(LOS)
Delay
(LOS)
Delay
(LOS)
1. Del Rio Rd/El Camino Real 69.3 (E) 111.9 (F) 111.9 (F) 23.2 (C) 23.2 (C) 29.5 (C)
2. Del Rio Rd/US 101 N Ramps 10.6 (B) 12.6 (B) 9.5 (A) 12.6 (B) 9.5 (A) 12.3 (B)
3. Del Rio Rd/US 101 S Ramps 19.5 (B) 22.3 (C) 22.5 (C) 22.3 (C) 22.5 (C) 25.1 (C)
4. Del Rio Rd/Ramona Rd 1.1 (A) 1.1 (A) 1.1 (A) 1.1 (A) 1.1 (A) 1.1 (A)
Northbound Approach 9.6 (A) 9.7 (A) 9.7 (A) 9.7 (A) 9.7 (A) 9.7 (A)
Notes: Delay is measured in average seconds per vehicle; LOS = Level of Service; Results for minor approaches to two-way
stop-controlled intersections are indicated in italics; Bold text = deficient operation; M1= Mitigation 1 ; M2 =
Mitigation 2; M3 = Mitigation 3; M4 = Mitigation 4 ; Mitigations are described in the text above.
Finding – With the addition of the Amended Specific Plan scenario traffic to the current configurations, the
intersection of Del Rio Road/El Camino Real would continue to operate unacceptably though at LOS F instead of
at LOS E without the added traffic. The modifications to this signal detailed above under Mitigations 2, 3, or 4
would improve operation to LOS C. The other study intersections would operate acceptably under Future
Conditions, with or without the Amended Specific Plan traffic and under any of the mitigation scenarios.
Queuing Analysis
Under each scenario, the projected maximum queues at the study intersections were determined using the
SIMTRAFFIC application of Synchro and averaging the maximum projected queue for each of five runs.
Summarized in Table 8 are the predicted queue lengths for approaches to intersections where queues are
expected to exceed the existing available storage capacity. Copies of the SIMTRAFFIC projections are contained
in Appendix B.
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Traffic Analysis for the Del Rio Specific Plan Amendment Traffic Analysis
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Table 8 – Queuing Analysis (Amended Specific Plan)
Study Intersection
Approach
Available PM Peak Maximum Queue Length
Storage E F F + Amended Specific Plan
NM M1 M2 M3 M4
1. Del Rio Rd/El Camino Real
Northbound Left-Turn 280 155 286 397 374 250 256 221
Southbound Left-Turn 150 25 35 43 32 36 31 45
Southbound Right-Turn - - 76 91 81 92 94 111
Eastbound Approach 240 154 210 272 256 280 268 204
2. Del Rio Rd/US 101 N Ramps
Westbound Approach 240 84 148 202 96 215 93 58
Eastbound Approach 290 99 195 279 210 263 208 213
Northbound Approach 470 88 97 115 118 128 130 128
3. Del Rio Rd/US 101 S Ramps
Westbound Approach 290 98 132 132 138 127 137 284
Eastbound Approach – Exist 35 115 - - - - - -
Eastbound Approach – Future 240 - 111 119 118 134 125 166
Southbound Approach 530 192 362 539 445 333 366 323
4. Del Rio Rd/Ramona Rd
Westbound Approach – Exist 35 79 - - - - - -
Westbound Approach – Future 240 - 27 30 27 31 38 40
Notes: Maximum Queue based on the average of the maximum value from five SIMTRAFFIC runs; all distances are
measured in feet; E = existing conditions; F = future conditions; F+ASP = future plus Amended Specific Plan
conditions; NM = no mitigation; M1 = Mitigation 1; M2 = Mitigation 2; M3 = Mitigation 3; M4 = Mitigation 4;
Mitigations are described in the text above; Bold text = queue length exceeds available storage
With the planned shifting of Del Rio Road/Ramona Road to the west, the distance between this intersection and
Del Rio Road/US 101 South Ramps would increase to accommodate queues under all assessed scenarios.
Under Future Conditions without traffic that would be generated by the Amended Specific Plan developments,
the northbound left-turn queue at Del Rio Road/El Camino Real of 286 feet would slightly exceed the provided
capacity of 280 feet. The addition of the Amended Specific Plan traffic would increase this queue overage to 397
feet without any mitigations applied, and would require Mitigations 2, 3, or 4 to reduce the queue length to remain
within the provided storage capacity.
The eastbound approach queue at Del Rio Road/El Camino Real would be within the 240 feet provided between
this intersection and Del Rio Road/US 101 North Ramps, at 210 feet under Future Conditions. With the addition of
the Amended Specific Plan traffic, this would increase to 272 feet without mitigation, representing an extension
of stopped traffic upstream and into the Del Rio Road/US 101 North Ramps intersection. Mitigation 4 would be
required to reduce this queue sufficiently to avoid stacking into the upstream intersection.
Finding – With the addition of the Amended Specific Plan scenario traffic, Mitigation 4 would be required to
reduce queuing to acceptable lengths.
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Traffic Analysis for the Del Rio Interchange
August 26, 2020
Buildout of the Amended Specific Plan with Regional Shopping
The Buildout of the Amended Specific Plan with Regional Shopping Center scenario shares many similarities to
the Amended Specific Plan. The key difference is that the regional shopping center use would be included on the
Walmart site.
Trip Generation
The anticipated vehicle trip generation for the proposed land uses was estimated based on standard rates for
“Hotel” (ITE LU 310), “High-Turnover (Sit-Down) Restaurant” (ITE LU 932), “Shopping Center” (ITE LU 820), “Business
Park” (ITE LU 770), and “Multifamily Housing (Low-Rise)” (ITE LU 220). Reductions for pass-by trips were applied
using the same methodology detailed under the Amended Specific Plan scenario.
The expected trip generation potential for the proposed uses is indicated in Table 9, with deductions taken for
pass-by trips. The proposed scenario is expected to generate an average of 9,411 trips per day at the driveways,
including 334 trips during the a.m. peak hour and 745 during the p.m. peak hour. After deductions are taken into
account, the scenario would be expected to generate 9,383 new trips on a daily basis, including 331 during the
morning peak hour and 743 during the evening peak hour; these new trips represent the increase in traffic
associated with the scenario compared to existing volumes.
Table 9 – Trip Generation Summary for Amended Specific Plan with Regional Shopping Center
Land Use Units Daily AM Peak Hour PM Peak Hour
Rate Trips Rate Trips In Out Rate Trips In Out
Annex West
Hotel 120 rms 8.36 1,003 0.47 56 33 23 0.60 72 37 35
Annex East
Business Park 190 ksf 12.44 2,364 0.40 76 46 30 0.42 80 37 43
Walmart Site
Regional Shopping Center 129.56 ksf 37.75 4,891 0.94 122 76 46 3.81 494 237 257
Sit-Down Restaurant 5 ksf 112.18 561 9.94 50 28 22 9.77 49 30 19
Pass-by -5% -28 -5% -3 -2 -1 -5% -2 -1 -1
Retail Pad 5 ksf 37.75 189 0.94 5 3 2 3.81 19 9 10
Apartments 55 du 7.32 403 0.46 25 6 19 0.56 31 20 11
Subtotal 9,411 334 192 142 745 370 375
Reductions -28 -3 -2 -1 -2 -1 -1
Total 9,383 331 190 141 743 369 374
Note: rms = rooms; du = dwelling unit; ksf = 1,000 square feet
Trip Distribution
The pattern used to allocate new scenario trips to the street network was based on existing traffic patterns. The
applied distribution assumptions and resulting trips are shown in Table 10.
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Traffic Analysis for the Del Rio Specific Plan Amendment Traffic Analysis
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Table 10 – Trip Distribution Assumptions for Amended Specific Plan with Regional
Shopping Center
Route Percent Daily Trips AM Trips PM Trips
US 101 North of Del Rio Road 35% 3,284 116 260
US 101 South of Del Rio Road 35% 3,284 116 260
El Camino Real South of Del Rio Road 15% 1,408 48 112
El Camino Real North of Del Rio Road 5% 469 17 37
Del Rio Road West of Ramona Road 5% 469 17 37
Del Rio Road East of El Camino Real 5% 469 17 37
TOTAL 100% 9,383 331 743
Potential Interchange Improvements
To assess what mitigations might be required to accommodate the trips that would be generated by the Amended
Specific Plan scenario, four mitigation scenarios were assessed. Mitigations 1, 2, and 3 are the same as detailed for
the Amended Specific Plan scenario. Mitigation 4 was specific to the Amended Specific Plan scenario, so was not
included for this scenario; it was replaced with Mitigation 5 which is specific to this scenario. Mitigation 5 includes
widening on the Del Rio Road overpass to accommodate the extra traffic that would be generated by the regional
shopping center:
Mitigation 5 – This option includes any modifications that would be required to achieve acceptable operations
with the addition of traffic that would be generated by the Amended Specific Plan Plus Regional Shopping
scenario. Along with applying Mitigation 1 and Mitigation 2, the eastbound approach to Del Rio Road/El Camino
Real would need to be widened to three lanes that extend upstream to Del Rio Road/US 101 North Ramps, with
one lane each assigned to left turns, throughs, and right turns. Likewise, the westbound approach would need to
be widened to include a right-turn pocket. A second northbound left-turn lane would be required to
accommodate traffic leaving the shopping center and heading toward the freeway. With these lanes added and
appropriate U-turn restrictions, southbound and eastbound right-turn overlaps could be added to further improve
traffic flow. The Del Rio Road overpass would need to be widened to four lanes, with a through/left-turn combined
lane and through lane approaching eastbound to Del Rio Road/US 101 North Ramps and left-turn and
through/left-turn combined lanes on the westbound approach to Del Rio Road/US 101 South Ramps. At Del Rio
Road/US 101 South Ramps, the southbound approach would need to be expanded to include an additional left-
turn lane, and the phasing would need to be modified to split the eastbound and westbound approaches.
Interconnect would need to be provided between all three signals to coordinate cycles.
Operational Analysis
Upon the addition of scenario-related traffic to the Future volumes, the three signalized study intersections would
operate unacceptably and require Mitigation 5 to achieve LOS C or better operation. These results are summarized
in Table 11, and LOS worksheets are included in Appendix A.
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Traffic Analysis for the Del Rio Interchange
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Table 11 – Future plus Amended Specific Plan plus Regional Shopping PM Peak Hour Intersection Delay
Study Intersection
Approach
Future Future plus ASP plus Regional Shopping
No
Mitigation M1 M2 M3 M5
Delay (LOS)
Delay
(LOS)
Delay
(LOS)
Delay
(LOS)
Delay
(LOS)
Delay
(LOS)
1. Del Rio Rd/El Camino Real 69.3 (E) 182.2 (F) 182.2 (F) 46.4 (D) 46.4 (D) 32.2 (C)
2. Del Rio Rd/US 101 N Ramps 10.6 (B) 38.9 (D) 12.4 (B) 38.9 (D) 12.4 (B) 9.4 (A)
3. Del Rio Rd/US 101 S Ramps 19.5 (B) 35.0 (D) 35.4 (D) 35.0 (D) 35.4 (D) 25.6 (C)
4. Del Rio Rd/Ramona Rd 1.1 (A) 1.1 (A) 1.1 (A) 1.1 (A) 1.1 (A) 1.1 (A)
Northbound Approach 9.6 (A) 9.8 (A) 9.8 (A) 9.8 (A) 9.8 (A) 9.8 (A)
Notes: Delay is measured in average seconds per vehicle; LOS = Level of Service; Results for minor approaches to two-way
stop-controlled intersections are indicated in italics; Bold text = deficient operation; M1 = Mitigation 1 ; M2 =
Mitigation 2 ; M3 = Mitigation 3; M5 = Mitigation 5; Mitigations are detailed in the text above.
The intersection of Del Rio Road/El Camino Real would operate at LOS E under Future Conditions without the
additional development associated with the Specific Plan, which would degrade to LOS F with the addition of
traffic from buildout of the Amended Specific Plan Plus Regional Shopping scenario without mitigation or with
Mitigation 1. Mitigations 2 and 3 would improve operation to LOS D, which would still be unacceptable under
current standards. Mitigation 5 would reduce the delay to achieve an acceptable LOS C operation.
For Del Rio Road/US 101 North Ramps, the addition of the Amended Specific Plan Plus Regional Shopping scenario
traffic to Future Conditions would degrade operations to LOS D. Mitigations 1, 3 or 5 would reduce delays at this
intersection respectively to achieve operation of LOS B, LOS B, or LOS A.
The addition of the Amended Specific Plan Plus Regional Shopping scenario traffic to Del Rio Road/US 101 South
Ramps would worsen the LOS B operations under Future Conditions to LOS D. This LOS D would be sustained
with Mitigations 1, 2, or 3, and would be improved to an acceptable LOS C with Mitigation 5.
The intersection of Del Rio Road/Ramona Road would operate acceptably under all scenarios assessed.
Finding – The addition of the Amended Specific Plan Plus Regional Shopping scenario traffic would result in
unacceptable delays at Del Rio Road/El Camino Real, Del Rio Road/US 101 North Ramps, and Del Rio Road/US 101
South Ramps. Mitigation 5 would be required to improve operations at all locations to LOS C or better.
Queuing Analysis
Under each scenario, the projected maximum queues at the study intersections were determined using the
SIMTRAFFIC application of Synchro and averaging the maximum projected queue for each of five runs.
Summarized in Table 8 are the predicted queue lengths for all approaches to intersections. Copies of the
SIMTRAFFIC projections are contained in Appendix B.
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Traffic Analysis for the Del Rio Specific Plan Amendment Traffic Analysis
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Table 12 – Queuing Analysis (Amended Specific Plan plus Regional Shopping)
Study Intersection
Approach
Available PM Peak Maximum Queue Length
Storage E F F+ASP plus Regional Shopping
NM M1 M2 M3 M5
1. Del Rio Rd/El Camino Real
Northbound Left-Turn 280 155 286 330 330 330 396 181
Southbound Left-Turn 150 25 35 49 38 47 39 58
Southbound Right-Turn - - 76 91 97 90 117 97
Eastbound Approach 240 154 210 307 307 305 300 165
2. Del Rio Rd/US 101 N Ramps
Westbound Approach 240 84 148 267 134 270 151 54
Eastbound Approach 290 99 195 436 447 430 367 129
Northbound Approach 470 88 97 225 326 110 202 145
3. Del Rio Rd/US 101 S Ramps
Westbound Approach 290 98 132 157 163 154 188 116
Eastbound Approach – Exist 35 115 - - - - - -
Eastbound Approach – Future 240 - 111 145 150 151 123 172
Southbound Approach 530 192 362 1119 1196 1115 1218 331
4. Del Rio Rd/Ramona Rd
Westbound Approach – Exist 35 79 - - - - - -
Westbound Approach – Future 240 - 27 26 30 28 32 43
Notes: Maximum Queue based on the average of the maximum value from five SIMTRAFFIC runs; all distances are
measured in feet; E = existing conditions; F = future conditions; F+ASP = future plus Amended Specific Plan; NM =
no mitigation; M1 = Mitigation 1; M2 = Mitigation 2; M3 = Mitigation 3; M4 = Mitigation 4; Mitigations are
described in the text above; Bold text = queue length exceeds available storage
As under the Amended Specific Plan scenario, shifting Del Rio Road/Ramona Road to the west would increase the
distance between this intersection and Del Rio Road/US 101 South Ramps to accommodate queues under all
assessed scenarios.
While the addition of Future volumes would increase the northbound left-turn queue length at Del Rio Road/ El
Camino Real past the 280 feet available to 286 feet, traffic that would be added by the Amended Specifc Plus plus
the regional shopping center land uses would extend this length to 330 feet. Only Mitigation 5 with its second
northbound left-turn lane would provide adequate storage capacity.
For the eastbound approach to Del Rio Road/El Camino Real, the addition of the Amended Specific Plan Plus
Regional Shopping scenario traffic would increase stacking length to 307 feet, such that the back of queue would
extend upstream into the intersection of Del Rio Road/US 101 North Ramps as there is only 240 feet between these
intersections. Mitigation 5 is the only mitigation assessed that would reduce this queue to a length that would
not extend into the upstream intersection, at a projected length of 165 feet.
The addition of the Amended Specific Plan Plus Regional Shopping scenario traffic would increase the westbound
queue approaching Del Rio Road/US 101 North Ramps to 267 feet, surpassing the 240 feet available between this
.
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Traffic Analysis for the Del Rio Interchange
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intersection and the upstream intersection of Del Rio Road/El Camino Real. The added westbound right-turn lane
from Mitigations 1, 3, or 4 would reduce this to an acceptable 134 feet, 151 feet, or 54 feet, respectively.
With 290 feet available between Del Rio Road/US 101 South Ramps and Del Rio Road/US 101 North Ramps, the
addition of the Amended Specific Plan Plus Regional Shopping scenario traffic would increase the eastbound
queue under Future Conditions approaching Del Rio Road/US 101 North Ramps from 213 feet to an unacceptable
436 feet, through and well past the intersection of Del Rio Road/US 101 South Ramps. This would be reduced to
129 feet under Mitigation 5; the other options would not reduce queuing to fit within the available stacking space.
There is 960 feet available between Del Rio Road/US 101 South Ramps and the US 101 South mainline, but a length
of 530 feet for queuing in order to account for deceleration from the gore point to the back of queue on the ramp.
The southbound queue would increase from 192 feet under Existing Conditions to 323 feet under Future
Conditions. However, the addition of the Amended Specific Plan Plus Regional Shopping scenario traffic would
further increase this queue length to 1,119 feet, representing unacceptable spillback onto the US 101 South
mainline. This spillback would continue to occur with Mitigations 1, 2 or 3, but would be eliminated under
Mitigation 5 which would reduce queuing to 331 feet.
Finding – Mitigation 5 would be required to reduce queues to acceptable lengths with the addition of the
Amended Specific Plan Plus Regional Shopping scenario traffic to Future Conditions.
Alternative Finding – In March 2012, W-Trans presented to the City of Atascadero the Del Rio Road Area Specific
Plan Transportation Impact Analysis. In this report, which assessed a similar scenario to the Amended Specific Plan
Plus Regional Shopping scenario, it was concluded that three roundabouts would be required to achieve
acceptable operations, covering the intersections of Del Rio Road/El Camino Real, Del Rio Road/US 101 North
Ramps, and Del Rio Road/US 101 South Ramps combined with Ramona Road. With these roundabouts, the
existing Del Rio Road overpass bridge could be maintained. This roundabout mitigation alternative would also
result in acceptable traffic conditions for the Amended Specific Plan Plus Regional Shopping Center scenario.
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Traffic Analysis for the Del Rio Specific Plan Amendment Traffic Analysis
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Conclusions and Recommendations
Existing Conditions
Under Existing Conditions, the study intersections operate acceptably, and most queue lengths are within
available storage. The exception is between Del Rio Road/US 101 South Ramps and Del Rio Road/Ramona
Road, where the queues in each direction exceed the 35 feet available between the intersections.
Future Conditions
A Future Conditions scenario was developed using SLOCOG model data augmented with anticipated
developments in the study area. Under Future Conditions, the intersection of Del Rio Road/El Camino Real
would operate with unacceptably high delay and unacceptable queue lengths in the northbound left-turn
lane. However, the relocation of Del Rio Road/Ramona Road to provide 240 feet of spacing from Del Rio
Road/US 101 South Ramps would mitigate the unacceptable queues between these intersections.
Amended Specific Plan
The Amended Specific Plan scenario was developed to assess the buildout of the Amended Specific Plan for
the area around the Del Rio Road interchange.
Vehicle Trip Generation: The estimated trip generation of this scenario is 4,963 trips per day, including 208
a.m. peak hour trips and 277 p.m. peak hour trips.
Impacts: With the Amended Specific Plan scenario traffic operations and queuing at the intersection of Del
Rio Road/El Camino would be unacceptable based on the established thresholds.
Mitigation: The following mitigation measures would be needed to achieve acceptable operations and
queuing conditions:
Del Rio Road/El Camino Real – Traffic signal modifications and lane geometric changes as described in
Mitigation 4.
Del Rio Road/US 101 North Ramps – Add a westbound right-turn lane to provide two westbound lanes
on Del Rio Road from El Camino Real to US 101 North Ramps (as described in Mitigation 1) .
The maximum number of trips that can occur prior to the addition of the westbound right-turn lane at Del
Rio Road/US101 NB Ramps and traffic signal modifications at Del Rio Road/El Camino Real would be 134
weekday p.m. peak hour trips of the 277 total weekday p.m. peak hour trips. This level of traffic increase would
equate to the hotel in Annex West (72 weekday p.m. peak hour trips) plus 147 ksf of the Business Park in Annex
East (62 weekday p.m. peak hour trips).
It is recommended that if development of the hotel in Annex West and the Business Park in Annex East are
allowed to move forward, the traffic signal modifications described in Mitigation 4 at El Camino Real/Del Rio
Road intersection should be completed prior to occupancy of the Business Park.
.
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Traffic Analysis for the Del Rio Interchange
August 26, 2020
Amended Specific Plan Plus Regional Shopping Center
The Amended Specific Plan Plus Regional Shopping scenario was developed to assess an alternative to the
Amended Specific Plan scenario where a regional shopping center would replace several of the uses for the
Walmart Site.
Vehicle Trip Generation: The daily trip generation for this scenario is estimated to be 9,383 trips per day,
including 331 trips during the morning peak hour and 743 during the afternoon peak hour.
Impacts: With the Amended Specific Plan Plus Regional Shopping scenario traffic added, operations and
queuing at the intersections of Del Rio Road/El Camino, Del Rio Road/US 101 North Ramps and Del Rio
Road/US 101 South Ramps would be unacceptable based on the established thresholds.
Mitigation: The following mitigation measures would be needed to achieve acceptable operations and
queuing conditions:
Del Rio Road/El Camino Real – Traffic signal modifications and lane geometric changes including dual
northbound left-turn lanes (as described in Mitigation 5).
Del Rio Road between El Camino Real and US 101 North Ramps – Widen the section to five lanes (two
westbound lanes and three eastbound lanes (as described in Mitigation 5).
Del Rio Road overpass – Widen the overpass to four lanes (as described in Mitigation 5).
Del Rio Road/US 101 South Ramp – Add a second southbound left-turn lane (as described in Mitigation
5).
The maximum number of trips that can occur prior to the addition of the westbound right-turn lane at Del
Rio Road/US101 NB Ramps and traffic signal modifications at Del Rio Road/El Camino Real would be 134
weekday p.m. peak hour trips of the 277 total weekday p.m. peak hour trips. This level of traffic increase would
equate to the hotel in Annex West (72 weekday p.m. peak hour trips) plus 147 ksf of the Business Park in Annex
East (62 weekday p.m. peak hour trips), or 35 ksf of the Regional Shopping Center on the Walmart site (134
weekday p.m. peak hour trips).
It is recommended that if development of the hotel in Annex West and the Business Park in Annex East are
allowed to move forward, the traffic signal modifications described in Mitigation 4 at El Camino Real/Del Rio
Road intersection should be completed prior to occupancy of the Business Park.
Alternative Mitigation: Construction of a series of three roundabouts would provide adequate capacity and
acceptable queuing along the corridor. The existing Del Rio Road overpass structure could then be
maintained. These are the same mitigation measures identified in the original Del Rio Specific Plan.
The maximum number of trips that can occur prior to widening of Del Rio Road overpass or implementation
of the roundabouts would be 293 weekday p.m. peak hour trips of the 743 total weekday p.m. peak hour trips.
This level of traffic increase would equate to the hotel in Annex West (72 weekday p.m. peak hour trips) plus
the Business Park in Annex East (80 weekday p.m. peak hour trips) plus 37 ksf of the Regional Shopping Center
on the Walmart site (141 weekday p.m. peak hour trips). .
.
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Traffic Analysis for the Del Rio Specific Plan Amendment Traffic Analysis
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Study Participants and References
Study Participants
Principal in Charge Steve Weinberger, PE, PTOE
Associate Engineer Kevin Carstens, PE
Assistant Engineer Kimberly Tellez
Graphics Alex Scrobonia
Editing/Formatting Alex Scrobonia
Quality Control Dalene J. Whitlock, PE, PTOE
References
City of Atascadero General Plan 2025, Crawford Multari & Clark, Omni-Means, Lisa Wise Consulting, and City of
Atascadero Community Development Department, 2016
Del Rio Road Area Specific Plan Transportation Impact Analysis, W-Trans, 2012
Guide for the Preparation of Traffic Impact Studies, California Department of Transportation, 2002
Highway Capacity Manual, Transportation Research Board, 2010
Trip Generation Manual, 10th Edition, Institute of Transportation Engineers, 2017
Trip Generation Handbook: An ITE Recommended Practice, 3rd Edition, Institute of Transportation Engineers, 2014
.
Appendices on file with the City of Atascadero
.