HomeMy WebLinkAbout10-04-2016 Item 8, Bochum„j Council Memorandum
DATE: October 3, 2016
TO: City Council/Planning Commissioners
COUNCIL MEETING: ly — &J— 7.01 b
ITEM NO.: 2____ `
FROM: Timothy Scott Bochum, Deputy Director of Public Works
VIA: Katie Lichtig, City Manager
RECEIVED
OCT 04 2016
SLD CITY CLERK
SUBJECT: October 4, 2016 Study Session #2 — Mission Plaza Traffic Summary
1. ENC: 9-30-2016 CCAT Traffic Memorandum — Mission Plaza Project
Item #2 on tomorrow night's City Council agenda is a joint study session with the Planning
Commission to receive presentation on work completed to date on the Mission Plaza Assessment
and Master Plan, and to solicit input from the community, Commission and Council regarding the
various alternatives that have been developed.
The primary objective is to try and establish a preferred alternative for the project that will then
move forward for final environmental analysis and review by the various advisory bodies. As part
of that next stage, the environmental review will assess any traffic impacts that may arise from
modifications to Broad and Monterey Streets.
Because the changes to Mission Plaza do not, in and of themselves, create significant new
vehicular trips (full or partial closure would merely redistribute existing traffic) the project's traffic
assessment has been combined with the environmental work being conducted for the Palm-
Nipomo Parking Structure since that project would create new traffic in the vicinity. Central Coast
Transportation Consultants (CCTC) have been retained by the City to conduct this work.
Staff has received some inquiries if there is any information on potential traffic issues that may
arise from the Mission Plaza project that could affect the Study Session discussion for tomorrow
night - particularly if there are limiting factors that might affect input on a preferred alternative.
Attached you will find a summary by CCTC of background traffic information including prior
studies that have been conducted for the Mission Plaza Dog Leg and the Palm-Nipomo Structure.
There are two primary conclusions.
1. Traffic volumes in the Downtown area near the Mission Plaza project have diminished in
the last decade since the initial traffic assessment for the Dog Leg project was completed.
As such, the prior conclusions of the traffic impact study (TIS) remain valid today. That
prior conclusion was that even with full closure of the Dog Leg, the project would not
create any significant impacts in the vicinity of the project.
Study Session #2 Traffic Summa
2. The Mission Plaza expansion and Palm/Nipomo parking structure are not expected to
impact vehicular Level Of Service (LOS) based on the past analysis and comparison to
current traffic volumes and other potential transportation impacts will be described in the
TIS currently underway for the Palm/Nipomo parking structure.
In essence CCTC has concluded, and staff concurs, that the various options of the Mission Plaza
project would not create significant traffic impacts regardless of the alternative chosen. There
could be some minor impacts for various alternative modes but those will be analyzed as part of
the upcoming environmental work that is to be completed.
Finally, as part of the Circulation Element (CE) Update the Mission Plaza Extension was reviewed
as an alternative. Similar to the prior TIS conducted for the project, the CE assessment determined
that significant impacts would not occur as part of the project but project specific review should
take place when a preferred alternative is reached.
The final conclusion based on a review of these past studies updated for recent conditions is that
the various options for the Mission Plaza project would not cause significant traffic impacts for
any of the proposed alternatives.
\\chstore7\team\counci1 agenda reports\2016\2016-10-04\ss 2 council memo corrospondence.docx
MEMORANDUM
Date: September 30, 2016
To: Tim Bochum, City of San Luis Obispo Public Works
From: Joe Fernandez and Travis Low, CCTC
Subject: Mission Plaza Dogleg-Palm/Nipomo Structure Transportation History
This memorandum summarizes the past work related to the planned Palm/Nipomo parking structure and
changes to the Mission Plaza dogleg. The goal of this summary is to assist in the review of concepts under
consideration for the Mission Plaza dogleg. The summary is organized into three sections:
1. Review of past studies.
2. Traffic volume changes.
3. Conclusions related to the Mission Plaza expansion.
1. REVIEW OF PAST STUDIES
The City of San Luis Obispo Mission Platia Dogleg Project Technical Memorandum (Kimley-Horn and Associates, 2001)
evaluated the impact of a full closure of the Mission Plaza dogleg. The study noted that no major operational
impacts would result to studied intersections, which all operated at LOS B or better with the full Mission Plaza
dogleg closure. The study notes that the closure would result in a loss of driveway access to one residential
property, reduce the on -street parking supply by 20 spaces, and potentially create `dead ends' in the circulation
Pattern.
The Palm/Nipomo Parking Structure Transportation Impact Analysis Draft Report (Draft TIA, Fehr & Peers, 2012)
evaluated the transportation impacts of constructing a new 450 -space parking structure and 5,000 square feet
of commercial or office uses. The Draft TIA studied six intersections and the two parking structure entrances
and concludes that all would operate acceptably at LOS B or better with acceptable queueing. This study was
based on traffic counts collected in 2010.
Both of the above studies were conducted under the City's 1994 Circulation Element, which relied on vehicular
level of service to describe transportation conditions. The City's 2014 Circulation Element describes
transportation operating conditions in terms of level of service for autos, pedestrians, bicycles, and transit riders.
Studies underway for the current planning of the Palm/Nipomo parking structure and Mission Plaza dogleg
will evaluate potential impacts in accordance with the 2014 Circulation Element.
2. TRAFFIC VOLUME CHANGES
The traffic counts used in the past studies described above were compared to more recent counts collected by
the City where the study locations coincide. Table 1 summarizes traffic volume changes from 2001, 2010, 2014,
and 2016.
(805) 316-0101
895 Napa Avenue Suite A-6, Morro Bay, CA 93442
Table 1: Intersection
& Segment Comparsion
PM Peak Hour Entering Volume
Intersection
2001 2010 2014
2016
Palm/Chorro
1,219 895 759
836
Average Daily Traffic
Segment
2001 2014
2016
Palm between Ni omo and Broad
2,825 2,159
2,238
Chorro between Monterey and Palm
7,993 4,794
5,335
Table 1 shows a substantial decrease in traffic volumes from 2001 to 2016 at the locations where counts are
available. This indicates that the 2001 and 2012 studies' vehicular LOS analysis and conclusions would also
apply to 2016 conditions.
3. CONCLUSIONS
The Mission Plaza expansion and Palm/Nipomo parking structure are not expected to impact vehicular LOS
based on the past analysis and comparison to current traffic volumes. Other potential transportation impacts
will be described in the Transportation Impact Study currently underway for the Palm/Nipomo parking
structure.
Two concepts are under consideration for the Mission Plaza dogleg. One option would create a woonerf, which
would slow vehicle traffic while maintaining two-way vehicular flow. A woonerf typically eliminates curbs and
sidewalks and creates a linear plaza shared by pedestrians, bicycles, and vehicles. This option would likely reduce
vehicle volumes as drivers shift to faster routes. Based on the prior studies, the shifted vehicular volumes are
not expected to significantly impact nearby roadways. Conditions for pedestrians and bicyclists would improve
due to slower vehicle speeds, lower volumes, improved streetscape quality, and additional circulating space.
The second option would provide one-way southbound flow (into downtown) with diagonal parking on one
side. The one-way option would result in less dramatic changes to traffic patterns compared to the full closure
evaluated in 2001, and is therefore not expected to adversely impact vehicular LOS. Conditions for pedestrians
would be improved, while some cyclists would have to change routes.
Currently 10 bicycles use the dogleg segment during the PM peak hour, with six northbound and four
southbound. Conversion to one-way southbound traffic would shift the northbound bicycle trips to a parallel
route. Both Chorro Street and Nipomo Street are identified as Class III bike routes in the City's Bicycle
Transportation Plan (BTP). The BTP includes a planned bicycle boulevard on the segment of Broad Street
adjacent to Mission Plaza, as a part of the project that includes a grade -separated bike crossing of US 101. The
BTP would have to be amended if the dogleg is converted to one-way traffic.
In summary, neither of the options under consideration for the Mission Plaza dogleg are expected to
substantially degrade transportation conditions in the City.
Please let us know if you have any questions.
Central Coast Transportation Consulting September 30, 2016