HomeMy WebLinkAbout8.2 Attch 6 Traffic Memo 08-25-2011Public Works Department
MEMORANDUM
DATE: August 25, 2011
TO: Kristi Bascom, Principal Planner
FROM: Jaimee Bourgeois, Transportation & Operations Manager
SUBJECT: Traffic Impact Review for CUP Application for Montessori Plus, PLPA-2011-
00013/00014 (FCN 030-885)
Montessori Plus has submitted an application for a Conditional Use Permit to occupy the building at
11900 Silvergate Drive as a daycare facility. The building was previously office use. The proposal
includes the use of 5,113 square feet to accommodate up to 60 children during the hours of 7:30 a.m.
and 6:30 p.m. This memorandum will examine trip generation of the proposed use compared to office
use, will review collision history in the vicinity of the project on Silvergate Drive, and will provide an
assessment of the sight distance at the project driveway on Dublin Green Drive.
Trip Generation Comparison
The 7,082-square foot building was previously used as office space. As shown in Table 1, this
corresponds to an estimated trip generation (including inbound and outbound trips) of 78 daily trips, 11
a.m. peak hour trips and 11 p.m. peak hour trips. The proposed daycare use would occupy 5,113 square
feet and accommodate up to 60 children. The proposed daycare use would generate 269 daily trips, 48
a.m. peak hour trips and 49 p.m. peak hour trips. This results in a net increase of 191 daily trips, 37 a.m.
peak hour trips and 39 p.m. peak hour trips.
TABLE 1
Trip Generation Comparison.
Land Use (ITE Codel) Size Daily AM Peak Hour PM Peak Hour
Existing -Office (710) 7,082 SF 78 11 11
Proposed -Daycare (565) 60 children 269 48 49
Net Difference + 191 + 37 + 39
Note:
1. Trip generation rates taken from the Institute of Transportation Engineers' Trip Generation
manual (8`'' Edition) base upon the specified land use code. All rates used are average rates.
Attachment 6
The additional traffic generated by the proposed project will likely be noticeable by neighbors. Plus,
some parents may decide to park on-street, so there will be more noticeable activity in the area. The
additional traffic, however, is not expected to exceed the capacity of the roadway or create any safety
hazards.
Traffic Collision Review
The last City-wide Traffic Safety Study was conducted for the period of 2006 through 2008. No portion
of Silvergate Drive was identified as a problem roadway. Because that study is a few years old, staff
conducted an updated review of the collision history on Silvergate Drive in the vicinity of the project
over the last five years. The results are summarized in Table 2. Looking at Silvergate Drive west of San
Ramon Road to west of Dublin Green Drive, there have been six collisions over a five year period,
including one in 2007, two in 2008, two in 2010 and one in 2011. While traffic collisions are expected
to happen, the quantity and type do not indicate that there is a safety problem at this location.
Year
.2006
2007
2008
2009
2010
2011
TABLE 1,
Collision History -Silvergate Drive Near Project Site
No. of Location Type of Collisions
Collisions
0 =
1 East of Arbor Creek Circle Driving eastbound, hit parked car, hit and run
2 East of Arbor Creek Circle
West of San Ramon Road
0 -
Driving eastbound, nighttime., hit parked car,
: unsafe speed
Vehicle turning left from San Ramon Road
.onto Silvergate Drive, hit fixed object to avoid
pedestrian, dark
2 West of San Ramon Road 'Vehicle turning right from San Ramon Road
:onto Silvergate Drive, hit fixed object, DUI
West of San Ramon Road Hit fixed object, unsafe speed, resulting
'immediately after collision. above
1 West of Dublin Green Drive Vehicle/pedestrian, dark, pedestrian did not
yield the right-of-way
Sight Distance
The sight distance for the egress driveway on Dublin Green Drive was examined. As illustrated in
Figure 1, sight distance is limited due to the fence and thick vegetation. If an exiting motorist stops
behind the sidewalk, he/she cannot see vehicles in the roadway approaching from the north and has very
limited sight of pedestrians on the sidewalk to the north. Upon pulling forward, visibility improves, as
illustrated in Figure 1 (far right photo). To insure safe interaction between pedestrians and exiting
vehicles, it is recommended that a stop line, STOP legend, STOP sign and "PED XING" yellow warning
sign (on same post) be required of the applicant for installation at the driveway. This will help remind
motorists to stop behind the sidewalk. Upon stopping, sufficient line of sight is available to determine
whether there is an approaching pedestrian. Motorists can then proceed forward slowly to improve line
of sight of the roadway.
Please let me know if you have any questions.
Cc: Mark Lander, City Engineer
G:\DEVELOPMEN7; PRIVATEWIontessori Plus, 11900 Silvergate Drive\Tra~c_Parking\memo_Montessori Plus_082511.doc
Figure 1-Photos looking north from project site driveway onto Dublin Green Drive