HomeMy WebLinkAbout2013-02-04; Traffic Safety Commission; ; Investigate the need to establish a STOP on Buttercup Road at its intersection with Carnation Drive-
COMMISSION MEETING OF:
CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
February 4, 2013 ITEM NO. 6B
LOCATION: Intersection of Carnation Drive and Buttercup Road
INITIATED BY: Ernest MacQuarrie
6903 Carnation Drive
Carlsbad, CA 92011
REQUESTED ACTION: Investigate the need to establish a STOP on Buttercup Road at its
intersection with Carnation Drive.
BACKGROUND
DATA:
Buttercup Road intersects Carnation Drive in a T-intersection configuration. This
intersection is located in a residential neighborhood with Buttercup Road being
considered the "stem" of the T-intersection. Carnation Drive is considered the "top" of
the T (see Exhibit 1). Currently this intersection is uncontrolled on all approaches and
staff is recommending that a STOP be established on Buttercup Road at Carnation Drive.
Carnation Drive and Buttercup Road are located in the southwest portion of the city.
Both streets are unclassified on the Circulation Element of the General Plan but function
as local streets based on street width and adjacent land uses. These streets serve a
residential neighborhood comprised of town homes. Carnation Drive and Buttercup
Road both have a curb to curb width of 40 feet and are fully improved with curb, gutter,
sidewalk and street lights on both sides of the streets. On-street parking is allowed on
both sides of Carnation Drive and Buttercup Road.
At T-intersections, it may be appropriate to put STOP control on the minor street leg.
One of the conditions that may warrant consideration of installing a stop sign on the
minor street is when the safe approach speed to the intersection is less than 10 miles
per hour. The minor street at this intersection is considered to be the stem of the T-
intersection, in this case, Buttercup Road. The major street is considered the top of
the T, in this case, Carnation Drive.
As drivers approach an uncontrolled intersection, right-of-way assignment is based on
the rules of the road. However, the driver should have an unobstructed view of the
entire intersection and there should be sufficient distance along the line of sight at the
intersecting street for the driver to anticipate and avoid conflicts with approaching
vehicles.
When a driver on the minor street is traveling towards the major street, a decision point
is required to determine whether braking to a stop is necessary because of an
approaching vehicle on the major street. This decision point location on the minor street
must allow the driver sufficient distance to view both the right and the left approaches
Page 1
r
COMMISSION MEETING OF:
(continued)
CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
February 4, 2013 ITEM NO.GB
on the major street. The driver on the minor street, generally not having the right-of-
way, can then initiate actions to slow, stop, or avoid a conflict with other vehicles, as
necessary, when sufficient corner sight distance is provided (see Exhibit 2).
For the analyses of local streets, the minor street decision point is assumed to be 50 feet
from the intersection given the vehicle on the minor street has an approach speed of
10 miles per hour. A distance of 150 feet (stopping sight distance for 25 miles per hour)
along the major street must be provided to minor street drivers to view vehicles
approaching the intersection.
At the study intersection, sight distance from Buttercup Road looking to the south was
measured to be 107 feet, which is less than the required 150 feet. This sight distance
limitation is due to vegetation on the southeast corner growing on private property.
Sight distance looking to the north was found to be 105 feet, which is also less than the
150 foot minimum requirement. This sight distance limitation is due to vehicles parking
on the east side of Carnation Drive north of Buttercup Road.
RECOMMENDATION:
Based on the findings contained in this report, the Traffic Safety Coordinating
Committee recommends the installation of a stop sign on Buttercup Road at its
intersection with Carnation Drive. This would include painting a limit line and a "STOP"
legend on the roadway.
NECESSARY CITY COUNCIL ACTION:
The City Council must adopt an ordinance to establish the STOP control as
recommended.
Page 2
C, ~
NOT TO SCALE
LOCATION MAP
£.\1. r,.'\J.
s G\~G PROPOSED
STOP
LEGEND:
~ SIGNALIZED INTERSECTION
,~ EXISTING STOP SIGN
!
l ..
I --------------------------------,
PROPOSED STOP ON BUTTERCUP ROAD EXHIBIT '
AT CARNATION DRIVE 1 } ____________________________ ..__ __ __.a
150' REQUIRED
107' MEASURED
-YEGETATION -REQUIRED -
LINE OF SIGHT
MEASURED
LINE OF SIGHT
I
150' REQUIRED
: rn;· """"" • 1
CONFLICT
POINT CARNATION
DECISION
POINT
DR/1,f
CARNATION
DR/1,f
CONFLICI
POINT1 ~r---------i---------:-:~~I9-----
-~Q:1.-------------REQUIRED nr--1=:, --~L~IN=E_.cOc'=F"'cSc-'-IG="H'=T
@
NOT TO SCALE
VEGETATION
a ~ c:, :::, ;§ co a::
DECISION
POINT
MEASURED
LINE OF SIGHT
DATE OF MEASUREMENTS: 11/7/12
CARNATION DRIVE AND BUTTERCUP ROAD
SIGHT DISTANCE ANALYSIS
EXHIBIT
2
! .,
l
! '------------------------------------'---~·