HomeMy WebLinkAbout7.3 DB@SlvrgtBike/PedLnGITY OF DUBLIN
AGENDA STATEMENT
City Council Meeting Date: January 9, 1989
SUBJECT:
Dublin Boulevard at Silvergate Drive
Bike/Pedestrian Lane Interim Revision
(Report by: Public Works Director Lee Thompson)
EXHIBITS ATTACHED:
Intersection diagram will be displayed at meeting
RECOMMENDATION: ,.~ ~/Receive report; authorize Staff to make interim
improvements.
FINANCIAL STATEMENT: Approximately $200 to make recommended changes.
DESCRIPTION:
At the November 28, 1988, City Council meeting, resident Dave Burton
stated that there was a potential traffic problem on the north side of Dublin
Boulevard at Silvergate Drive where the bike lane becomes very narrow.
Additionally, there is an asphalt berm at the far edge of the bike lane. Mr.
Burton said that he had nearly hit a bicyclist near this curve because the
bicyclist turned to look for approaching cars and when doing so, veered out
into the traffic lane. The City Council directed Staff to take a look at this
intersection and determine whether any interim improvement could be made that
would provide additional space for bicyclists and pedestrians, who must walk
along the shoulder of the road since there is no sidewalk at this portion of
Dublin Boulevard. The intersection will ultimately be redesigned in
conjunction with the Hansen Ranch development.
Staff made a field investigation at the intersection and found that the
present space allotted to bicyclists is approximately 2'6" wide at its
narrowest point. The traffic lane at this point is just over 14 feet wide,
which is wider than the Il-foot minimum requirement for a traffic lane. It
would therefore be possible to restripe the lanes to allow 4'6" for the bike
lane and still leave just over 12 feet for the traffic lane. The curve in the
bike lane stripe would need to be realigned in order to maintain the 4'6"
width.
A vertical curb between the bike lane and the traffic lane was discussed
but rejected because it would further constrict the already narrow lanes and
would add an obstruction for both bicyclists and vehicles.
Staff further proposes installation of a curve warning sign and an
advisory speed limit sign of 15 mph. This measure would serve as an
indication to both motorists and bicyclists that care should be taken when
passing through this area. The estimated cost of these improvements is
approximately $200.
GITY OF DUBLIN
MEMORANDUM
Date:
To:
From:
Subject:
January 3, 1989
Lee Thompson, Public Works Director
Steve Loweree, Maintenance Superintendent
Dublin Boulevard at Silvergate Drive
Attached is a diagram of proposed changes to this intersection,
particularly the bike lane. The changes are based on the knowledge that (1)
the minimum width of a traffic lane can be eleven (11) feet, (2) that this is
a bike lane (adjacent and contiguous with road surface) as opposed to a bike
path (5' minimum and physically separated from road surface by curb,
sidewalk, or right-of-way), and (3) the minimum width of a bike lane can be
four (4) feet. Based on this, we can realign the bike lane to a minimum of
4'6".
The narrowest point of the bike lane is 2'6" Adjacent to this point
is a through traffic lane that is 14'2" wide. The bike lane can be widened
to 4'6", thus narrowing the traffic lane to 12'2". The traffic lane would
still be over the minimum width needed. The bike lane stripe would need to
be realigned approximately 50 to 75' to maintain a 4'6" width. I feel that
widening the bike lane any more would make the travel lane too narrow, as it
is situated on a curve.
There are some additional steps for your consideration as well. First,
as discussed previously, would be the installation of warning signs for the
curve. Included would be a yellow 15 mph warning sign for the curve (see
diagram) in an attempt to slow down motorists and increase reaction time to
pedestrians/cyclists in the bike lane, as well as increase reaction time for
bike lane users to motorists. The location of these signs would need to be
further down the hill on Dublin Blvd. than the plan shows since space was
limited on the 8 1/2 x 11 sheet. The second item would be the installation
of a bike lane legend with arrow prior to the curve. This would just
reinforce the idea of a bike lane. The third item would be a "Slow Curve"
legend painted on Dublin Blvd. adjacent to the new warning signs.
Approximate costs for these items would be $200 - $300.
Finally, I feel that TJKM should review and comment on this plan for
any flaws. If you have any questions, please advise.
SL/gr
Attachment
cc: TJKM
{
/
DUSL~N
U~NF-
GLVD.
/
i
11
LEGEND J ~ REGULATORY SIGN j~--- ~FFlC SIGNAL
F/CEX~NSION ELEC~OLIER
~ST
A~
FACE OF C~B ~ANDARD ~~_
I)A'I f: ~ARY 7, 1986 ( AERIAL )
<~ N{,. I/y IMte Revisions INTERSECTION i ROJECT
DATE:
SCALE:
DESIGNED:
DRAWN:
CHECKED:
PROd. ENGR,:
F.B,:
REVISIONS
ENGINEERING
SANTINA ~
PLANNING
THOMPSON ~c.
1040 Oak Grove Road, Concord, California 94518 (415) 827-3200, Telex 338563 Santina
PREPARED
C TY OF
6500 DUBLIN
SUITE 101
DUBLIN
FOR:
DUBLIN
BOULEVARD
CALIFORNIA 94568
OF
SHEET
S HE :TS
JOB NO.