HomeMy WebLinkAbout2016-09-12; Traffic Safety Commission; ; Modify limits of existing 40 mile per hour speed zone on a portion of Black Rail RoadC
COMMISSION MEETING OF:
CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
September 12, 2016 ITEM NO. 6A
LOCATION: Black Rail Road from Poinsettia Lane to Sapphire Drive
Alex Amirnovin INITIATED BY:
5976 Black Rail Road
Carlsbad, CA 92011
REQUESTED ACTION: • Modify limits of existing 40 mile per hour speed zone on a portion
of Black Rail Road.
BACKGROUND:
DATA:
The Engineering and Traffic Survey currently on file for Black Rail Road justifies a 40 mile
per hour speed zone from Sapphire Drive to Aviara Parkway (see Exhibit 1). Based on
the presence of single family homes on a portion of Black Rail Road, staff is
recommending a modification to the limits of this speed zone so that Black Rail Road
between Sapphire Drive and Poinsettia Lane can be appropriately posted as a 25 mile
per hour speed zone.
The portion of Black Rail Road between Sapphire Drive and Poinsettia Lane is
approximately 1,100 feet in length and 40' wide curb to curb. Sapphire Drive is a
private gated street at the northern terminus of Black Rail Road which provides access
to the large Marbrisa community. There are six single family homes with frontage upon
Black Rail Road, which differentiates it from the other portions of Black Rail Road (see
Exhibit 2). The California Vehicle Code defines a "residence district" as,
"a portion of a highway and the property contiguous thereto, other than a business
district, (a) upon one side of which highway, within a distance of a quarter of a mile, the
contiguous property fronting thereon is occupied by 13 or more separate dwelling
houses or business structures"
Based on this definition, the required ratio to meet the residence district requirement is
13 houses per every quarter of a mile or approximately 1 house per 100 feet. Per
Section 22352 of the California Vehicle Code, a residence district street may be posted
with a prima facie 25 mile per hour speed limit without justification of an Engineering
and Traffic Survey.
The linear distance which encompasses the six homes on Black Rail Road is 560 feet.
This spacing meets the definition of residence district and therefore, can be
appropriately signed as a 25 mile per hour speed zone.
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RECOMMENDATION:
The Traffic Safety Coordinating Committee recommends modifying the limits of the
existing 40 mile per hour prima facie speed limit upon Black Rail Road so that the
portion of said roadway between Sapphire Drive and Poinsettia Lane can be
appropriately posted as a 25 mile per hour speed zone.
NECESSARY CITY COUNCIL ACTION:
An ordinance will be required to be adopted by the City Council to modify the limits of
the existing 40 mile per hour prima facie speed limit upon Black Rail Road
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CITY OF CARLSBAD -
ENGINEERING AND TRAFFIC SURVEY
STREET: Black Rail Road
LIMITS: Sapphire Drive to Aviara Parkway
FACTORS
A. Prevailing S11eed Data: Direction: Northbound/Southbound
Date of Speed Survey 3/17/15
Location of Speed Survey 0.1 Mile s/o Corte Orchidia
85th Percentile 40MPH
10 MPH Pace 32 to 42 MPH
Percent in Pace 75%
B. Accident History:
(8/01/13 through 7/31/15)
Speed-Related Accidents 2
Pedestrian and/or Bicycle Accidents 0
Total Accidents 2
C. Traffic Factors:
Average Daily Traffic 1,200 -North of Aviara Parkway (2008); 1,400 -South of Martingale Court (2008)
Traffic Controls Traffic Signals at Aviara Parkway and Poinsettia Lane
Pedestrian/Bicycle Traffic Low
Bicycle Lanes No Striped Bicycle Lanes
On-Street Parkina Parking Allowed on Both Sides
D. Roadway Factors:
Circulation Element Street Classification Unclassified
Length of Segment 0.85 Miles
Roadway Width Varies Between 36 Feet and 48 Feet
Number of Lanes One Lane Each Direction
Vertical Alignment Roadway Grades Vary from 1.00% to 8.19%
Horizontal Alignment Relatively Straight
Sidewalks Sidewalk on Both Sides Except 325 feet of East Side
Driveways 12 Driveways
Street Liahtina Limited Street Lighting
E. S11ecial Conditions: Travel lanes are separated by a 55-foot long raised median north of the intersection at Aviara Parkway and 1.
the remainder of the road has a double-vellow centerline.
F. Adlacent Land Uses: Two Water Reservoirs, Sinale-Familv Residential, Church, Ooen Soace
G. Remarks/Conditions Not Readilv Annarent: Vertical curves on Black Rail Road limit stonnina siaht distance.
H. Traffic Engineer's Recommendation {Explanation): This speed zone satisfies the conditions of Section 627 of the California
Vehicle Code and has been prepared and evaluated in accordance with the California Manual on Uniform Traffic Control
Devices, effective November 7, 2014, with respect to design and prevailing speeds, accident records, pedestrian and bicyclist
safety, intersection and driveway spacing, and roadside and traffic conditions not readily apparent to the driver. A speed limit
oostina of 40 MPH is found to be annrooriate and iustified.
I. A1111rovals:
~ecertification of existing speed zone per Sections 22357, 22358 and 40j 02 of the California Vehicle Code.
□ Establishment of new speed zone. ~M ·1,.
Approved I, Ul ii\. II loiolrS
Doug Bilse . (J Date
City Traffic Engineer
CATR2279
NOTE: Appropriate speed survey ,s attached hereto and made a part hereof.
DATE: 3/17/15 TIME: 10:10 AM. TO
WEATHER: Sunny & Mild
CITY OF CARLSBAD
SPEED SURVEY
12:05 P.M. TOTAL VEHICLES:
CRITICAL SPEED:
LOCATION: Black Rail Road-0.1 mi. s/o Corte Orchidia VEHICLES IN PACE:
OBSERVER/RECORDER: J. Gale =='-'--------PACE SPEED(S):
SOUTHBOUND
DIRECTION OF TRAVEL
MPH # % I:# % %tile % #
65
64
63
62
61
60
59
56
57
56
55
54
53
52
51
50
49
48
47
46
45 X X
44 X
43 X
42
41 X
40 X Jl
39 Jl X X X
36 X
37 X X X
36 X X
35 X X y X y X
34 X X X X y X
33 X
32 X X X X X X X
31 X X
30 X X
29 X
26 X
27 X X
26
25
24
23
22
21
1 1 100 2 1
99
2 4 4 4 99 4 2
1 2 1 1 95
1 2 3 3 94 4 2
3 3 91 6 3
1 2 3 3 88 4 2
2 4 3 3 85 2 1
4 8 6 6 82 4 2
1 2 7 7 76 12 6
4 8 7 7 69 6 3
3 6 9 9 62 12 6
7 14 13 13 53 12 6
7 14 9 9 40 4 2
2 4 6 6 31 8 4
7 14 11 11 25 8 4
2 4 4 4 14 4 2
2 4 2 2 10
1 2 3 3 8 4 2
1 2 1 1 5
2 4 3 3 4 2 1
1 1 1 2 1
Public Works Department
Traffic and Mobility Division
100
40 MPH ------'-''------
75 % -------'-"-----
31 TO 41 MPH -----
NORTHBOUND
DIRECTION OF TRAVEL
MPH
65
64
63
62
61
60
59
56
57
56
55
54
53
52
51
50
49
48
X 47
46
X X 45
44
X X 43
X X X 42
X X 41
X 40
X X 39
Jl X X X Jl X 38
X X X 37
X X Jl X X X 36
X X X X X X 35
X X 34
X X X X 33
X X X X 32
X X 31
30
X X 29
26
X 27
X 26
25
24
23
22
21
LOCATION MAP
NOT TO SCALE
Black Rail Speed Zone EXHIBIT
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