HomeMy WebLinkAbout2005-01-03; Traffic Safety Commission; ; Investigate the need for a STOP sign on Cadencia Street at its intersection with Romeria Street(
CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
COMMISSION MEETING OF: January 3, 2005
LOCATION: Cadencia Street at Romeria Street
INITIATED BY: Toni Kubilus
ITEMNO. 6A
REQUESTED ACTION: Investigate the need for a STOP sign on Cadencia Street at its
intersection with Romeria Street.
BACKGROUND:
Cadencia Street intersects Romeria Street in a T-intersection configuration.
This intersection is in a residential area with Cadencia Street being the stem of the
T-intersection (see Exhibit 1). No traffic control devices have been installed to assign the
right-of-way at this intersection.
DATA:
Cadencia Street and Romeria Street are both considered local streets and neither is
classified on the Circulation Element of the General Plan. Romeria Street provides a
through street connection between La Costa A venue and Levante Street and it also
provides direct access to and from La Costa Heights Elementary School.
When staff receives a request for STOP signs, the issue is reviewed thoroughly.
STOP signs can cause substantial inconvenience to drivers and are intended to be used
only where warranted. One of the conditions at an intersection that may warrant the
installation of a STOP sign on the minor street is when, for sight distance purposes,
the safe approach speed to the intersection is less than 10 miles per hour.
The safe approach speed analysis is typically evaluated when there is a request to install a
STOP sign on the minor street at an intersection. The minor street at a T-intersection is
generally considered to be the stem of the T-intersection with the major street being the
top of the T-intersection.
Each driver approaching an uncontrolled intersection has the intersection right-of way
assigned based upon the rules of the road. However, the driver should have an
unobstructed view of the entire intersection and sufficient sight distance along the
intersecting street for the driver to anticipate and avoid conflicts with approaching
vehicles.
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CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
COMMISSION MEETING OF: January 3, 2005
(continued)
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ITEMNO. 6A
A driver on the minor street (stem of the T-intersection), when approaching the major
street, reaches a decision point location when braking to a stop, or substantially slowing
the vehicle, is necessary if there is another vehicle approaching the intersection on the
major street. The location of the decision point on the minor street must allow the driver
to view, to the right and to the left, an approaching vehicle traveling on the major street.
The driver on the minor street, generally not having the right-of-way, can then slow, stop,
or avoid a conflict with other vehicles, as necessary, when the proper clear approach sight
triangle is provided (see Exhibit 2). Conversely, the driver on the major street can see the
approaching vehicle on the minor street when the clear approach sight triangle is
established.
On local streets, the minor street decision point location is assumed to be 50 feet from the
intersection for an approach speed of 10 miles per hour. In general, a distance of 155 feet
(stopping sight distance for 25 mph) along the major (local) street, or top of the
T-intersection, needs to be provided to view vehicles approaching the intersection.
However, when the grade of the major street exceeds 3 percent, a grade adjustment factor
is applied to the length of the sight distance. For the subject location, the major street
grade is 9.0% both north and south of the intersection. Therefore, an adjusted distance of
140 feet looking to the north (for vehicles traveling uphill) and an adjusted distance of
171 feet looking to the south (for vehicles traveling downhill) is necessary for the minor
street driver to view vehicles approaching the intersection. If the major street vehicle
cannot be seen by the driver at the decision point on the minor street, a STOP sign can be
considered for installation on the minor street to assign right-of-way.
At the Cadencia/Romeria location, the driver on the minor street, Cadencia Street, can
adequately see approaching northbound major street (Romeria Street) vehicles when they
are approximately 155 feet north of the intersection. However, approaching vehicles from
the south cannot be seen when they are 171 feet south of the intersection due to
landscaping. A driver can observe a vehicle on Romeria Street at a point only 70 feet to
the south from Cadencia Street due to landscaping on the southeast comer of the
intersection. Consequently, the 10-mile per hour safe approach speed criteria is not being
met and a STOP sign can be considered for installation on Cadencia Street, the minor
street.
For one short time period, staff observed driver behavior on westbound Cadencia Street
approaching Romeria Street to tum right or left. A total of 37 vehicles were noted during
the observation period. It was found that of the 29 left-turning vehicles, all but one of the
vehicles was considered "stopped" (slowed to a speed less than 10 mph). Of the eight
right-turning vehicles, all eight were considered "stopped" (slowed to a speed less than
10 mph). Staff observed that the one left-turning driver entering Romeria Street violated
the right-of-way of a northbound vehicle on Romeria Street.
CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
COMMISSION MEETING OF: January 3, 2005
( continued)
RECOMMENDATION:
ITEMNO. 6A
The Traffic Safety Coordinating Committee recommends installing a STOP sign on
Cadencia Street at its intersection with Romeria Street.
NECESSARY CITY COUNCIL ACTION:
It will be necessary for the City Council to adopt an ordinance to establish the STOP sign,
as recommended.
NOT TO SCALE
PROJECT NAME
LOCATION
LEVANTE
LEGEND:
LA COSTA
HEIGHTS ELEMENTARY SCHOOL
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MAP
0 PROPOSED STOP SIGN LOCATION
PROPOSED STOP SIGN
DRAl'tN BY: SCOTT EVANS, CARLSBAD ENGINEERING DEPT. 10/7/04 C: \TRAFFIC\STOP SIGNS\STOP S/GN-CADENCIA-ROMER/At.DWG
EXHIBIT
1
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171' REQUIRED (MAJOR STREET) ROMER/A ST.
70' ACTUAL
------7
I
I 50' I
I
REQUIRED I LINE OF
SIGHT NOT TO SCALE s;
-$~
NOT TO SCALE
(MAJOR STREET)
ROMER/A ST.
(..)
a5 GM/NOR) Cl STREET. o
i-:
U)
s;
(..)
a5
50'
Cl
O (MINOR)
\STREET
DECISION POINT
140' REQUIRED
• 155' ACTUAL
DECISION POINT
TITLE CADENCIA STREET I ROMER/A STREET
INTERSECTION APPROACH SIGHT TRIANGLE
DRAl+N BY: SCOTT EVANS, CARLSBAD ENGINEERING DEPT. 11 17 04 C: 7RAmc STOP SIGNS STOP S/GN-CADENCIA-ROMERIA2.DWG
EXHIBIT
2