HomeMy WebLinkAboutAttmt 5 Traffic Engr Memo
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MEMORANDUM
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From:
City of Dublin
ML Ray Kuzbari ¡
George Niekelsorþ./l1
CirculationfParkíng Plan Check
Date:
October 21, 2005
Emerald Place
To:
Attn:
Project
Re:
Job No.:
35-2807-36
File No,:
cc:
This memo summarizes our review of the circulation and parking characteristics as delineated in the
project plans for the Emerald Place retail project. In addition to the following text discussion, we have
attached three copies of the site plan with comments noted in red.
Aisle Width~:.
The plan shows 24-foot parking aisle widths throughout the development. This width meets the City
standard for perpendicular parking layout.'l)
Parking Soace Design:
The majority of the project's parking spaces appear to meet the City standard dimension of9' x 20'. There
also are a number of areas where compact spaces (8' x 17') are provided (see attached site plan). Thcre are
166 spaces that appear to be compact and another 30 spaces (see attached plan) that have stall depths
consistent with compact spaces. Compact spaces are generally better suited for the low turnover demand
generated by employees. The City Code allows lip to 35% compact spaces, but a retail project should
probably not exceed 20%, a factor which represents the typical employee parking demand at a shopping
center") A 20% compact ratio would limit the number of compact spaces to abollt 130 spaces (652 total
spaces x 20%).
Truck Access:
The site plan outlines extensive truck turn paths on many of the shopping center aisles. The vehicle
depicted on these turn paths is a 40-foot single unit truck, larger than the typical 30-35 foot single unit
truck. However, the site plan shows 65-foot tractor-trailer trucks (the Caltrans standard truck) parked in
the four larger truck docks within the project.!J) I have used a manual template depicting the turn paths of
these larger 65-foot trucks, and it appears that adequate tum paths are available to accommodate truck
access in/out urthe docks. The project engineer should confirm (on an updated site plan) that these larger
truck turn paths can in fact~ be accommodated.
1901 Otympic Blvd.. Walnut Creek, CA 94596 - (925) 935-2230 fax (925) 935-2247
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October 21,2005, Ray Kuzbari
Drivewav Access:
The radii for driveway curb returns are generally satisfactory with the exception of the southeast curb
return at the main driveway on "Entry Drive". This curb return appears to have a I 0 foot radius, and
national and Caltrans standards suggest a minimLUTI radius of 15-16 feet.(4X')
We are concerned that the driveway access on Martinelli Way would have a high potential for vehicle
conflicts. Within 40 feet of Martinelli Way, there would be full access openings to small parking lots on
both sides of the driveway. Vehicles attempting to turn left in/out of these lots would likely conOict with
inbound and outbound vehicles using the driveway. In particlllar, if 2-3 outbound vehicles are queued
waiting to turn right onto Martinelli, a vehicle tllrning left in or out of these lots would connict with these
qoeues and could block inbound traffic from Martinelli. We have sketched a potential alternative design,
including a raised median in the driveway and right turn in/out only access for the two adjacent parking
lots. This design would require a somewhat wider driveway, bllt it appears that the wider driveway and
median could be accommodated. Even with the suggested design changes, access/circulation could be
problematic for Building 201, a proposed 7,826 sq. ft. restaurant. 111e Code parking demand for this
restaurant would be 78 spaces, but the small lot immediately in front of the restaurant only contains 13
spaces. If restaurant customers enter this small lot, they are likely not to find available parking, requiring
an exit onto Martinelli Way and a reentry to the Center. Consideration should be given to shifting the
restaurant westerly and elim inating the small parking lot. The restaurant's entrance could face the parking
lot to the east, the primary location for this restaurant's parking.
Internal Traffic Controls:
Generally, low volume low speed internal roadways do not require extensive tral1ìc controls. It would,
however, be appropriate to install stop sign controls at several key locations. As shown on the attached
site plan, the two main driveways on Martinelli Way and Entry Drive shuuld not be stopped at the first
internal intersection. Inste.1d, the side aisle should have two-way stop sign controls. At the center of the
project, the intersection would benefit from all-way stop sign controls.
I tmst that this review responds to your needs. Please call me with any questions or comments or if further
input is required.
References:
(I) City of Dublin, City of Dublin Zoning Ordillallce- Chapter 8.76 Off-Street Parkillg ami Loadillg
Regulatiolls, Amended July 15, 2003.
(2) Urban Land Institute, Parking Requiremellts for Shopping Celllers- Second Edit ion, 1999.
(3) Caltrans, Highway De.,igll Mallual- Fifth Editioll, July 1,2004.
(4) American Association of Slate Highway and Transportation Officials (AASHTO), A Policy 011
Geometric Design of Hfghways and Streets, /984.AASHTO specifies a 15-foot minimum radius
for curb returns.
(5) Callrans, ibid. Caltrans specifies a 5-meter (about 16-foot) minimum radius for curb reulrns.
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1901 Olympic Blvd., Walnut Creek. CA 94596 - (925) 935-2230 fax (925) 935-2247