HomeMy WebLinkAboutNB 4 MEDIAN MOD. 10-04-82AGENDA
DATE:
SEPTEMBER 29, 1982
NEW BUSINESS
NO. 4
10-4-82
Inter-Corn
TO:
WILLIAM HUSTON, CITY MANAGER
FROM: BOB LEDENDECKER, DIRECTOR OF PUBLIC WORKS/CITY ENGINEER
SU8J£CT: NEWPORT AVENUE MEDIAN ISLAND MODIFICATION
RECOMMENDATION:
That the Tustin City Council, at their meeting of October 4, 1982, direct staff to
proceed with implementation of Alternate No. 2 at the intersection of Newport
Ave. and First St. and further direct staff to include Alternate No. I at the
intersection of Newport Ave. and Mitchell Ave. for inclusion and implementation
into the 1983-84 Capital Improvement Budget.
BACKGROUND:
At a recent meeting, the City Council requested staff to review the left turn
pocket for northbound Newport Avenue at First Street with respect to enlargement
of the pocket. In reviewing this left turn pocket at First St., staff has also
reviewed the southbound left turn pocket on Newport Avenue at Mitchell Ave. which
also experiences vehicles extending out of the pocket and into the number one
southbound lane of Newport Ave.
Prior to when the median islands were initially installed, meetings were held with
all of the affected businesses along Newport Ave. with respect to access to and
from various parcels which ultimately governed the length of the majority of left
turn pockets and more particularly the two in question. The median island
configuration that exists today is the one that was approved by both the majority
of the adjacent property owners and the City Council.
DISCUSSION:
New~o~t Ave. at First St.
There are four alternatives to help reduce the problem of vehicles extending
outside of the left turn pocket and into the number one lane as follows:
Alternate #1 - Protected Left Turn Phase
This alternate would provide a protected separate left turn phase. This
change can be accomplished with minor wiring modifications. This
modification has a potential for increasing the present problem, depending
upon the amount of green time allotted to the left turn phase with respect to
total green time for through movements on Newport Avenue. The estimated cost
for this change is $800.00.
Alternate ~2 - Permissive Left Turn Movement
Change the existing leading protected left turn movement to a lagging
protected left turn movement. All equipment necessary is on-site and this
change will require only a minor cabinet wiring change. Cost for this change
is estimated at $200.00 per controller.
NEWPORT AVENUE MEDIAN ISLAND MODIFICATION
SEPTEMBER 29, 1982
~AGE TWO
Alternate #2 - (Continued)
This alternative may not totally solve the problem of vehicles extending into
the number one lane from the left turn pocket,, but it will clear the pocket
at the end of each cycle.
It is recommended that all intersections along Newport Ave. between and
inclusive, of Irvine Blvd. and E1Camino Real/Laguna Rd. be changed to this
operation for continuity, if this option is selected.
Alternate #3 - Lengthen the Existing Left Turn Pocket
~his alternate would require the modification of the island consisting of
relocatilon/replacing the landscaped area (tree and dichondra) of the island
southerly, Cost of this change is estimated at $9,500.00. No modification
of the traffic signal would be required.
The major disadvantage of
ingress and egress to and
Newport Ave, southerly of
driveway of Larwin Square
this alternate would be the deletion of left turn
from the medical buildings on the easterly side of
First St, and to and from the most northerly
(between Bank of America and Burger King).
This alternative would solve the problem of vehicles extending out of the
left turn pocket into the number one lane of northbound Newport Ave.
Alternate #4 - Utilization of Double Left Turn Lanes
This alternative would add a second left turn only lane for northbound
Newport Avenue, This option would shift the through traffic on Newport Ave.
easterly and would require the removal of on-street parking on the easterly
side of Newport Ave, for a distance of 300 feet southerly and northerly of
First St. This parking removal would affect the area between Holt Ave. on
the north and the Centre Pharmacy on the south. It appears that all of these
businesses on the east side of Newport Ave. have sufficient on-site parking.
The estimated cost for this alternative is $1,800,00 for modification of loop
detection, restriping and signing.
Mitchell Avenue
There are two alternatives to help reduce the problem of vehicles extending
outside of the left turn pocket and into the number one lane as indicated below.
The double }eft turn lane cannot be used at this intersection because of the
narrow width of Mitchell Avenue.
Alternate #1 - Left Turn Phasing
This alternative will require major signal equipment modification due to the
old equipment presently installed at the intersection. The total estimated
cost for this equipment is $24,000.00.
It is suggested that this alternative might be considered as a Capital
Improvement Project in 1983-84.
NEWPORT AVENUE MEDIAN ISLAND MODIFICATION
SEPTEMBER 29, 1982
PAGE THREE
Alternate #2 - Lengthen the Existing Left Turn Pocket
This alternative would require the modification of the island consisting of
relocation/replacing the landscaped area (tree and dichondra) of the island
northerly. Cost of this change is estin~lted at $9,500.00. No modification
of signal equipment would be required; however, with the older existing
signal equipment, the left turn pockets may not be cleared with each cycle.
The major disadvantage of this alternate would be the deletion of left turn
ingress and egress to and from both remaining driveways of the dairy and the
southerly drive of the gas station on the westerly side of Newport Ave., and
to the northerly driveway of Taco Bell and the southerly driveway of the
sandwich and donut shops on the easterly side of Newport Ave. northerly of
Mitchell Ave.
This alternative would solve the problem of vehicles extending out of the
left turn pocket into the number one lane of southbound Newport Ave.
BOB LEDENDECKER
DIR£CTOR OF PUBLIC WORKS/
CITY ENGINEER
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