HomeMy WebLinkAbout2010-12-06; Traffic Safety Commission; ; Revise the prima facie speed limit upon Loker Avenue West, from Palomar Airport Road to El Fuerte StreetI"""
CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
COMMISSION MEETING OF: December 6, 2010 ITEM NO. 6B
LOCATION:
INITIATED BY:
Loker A venue West from Palomar Airport Road to El Fuerte Street
Traffic Division Manager
REQUESTED ACTION: Revise the prima facie speed limit upon Loker Avenue West, from
Palomar Airport Road to El Fuerte Street.
BACKGROUND:
Currently, this portion of Loker Avenue West is posted at 30 miles per hour. The
Engineering and Traffic Survey on file was approved on September 12, 2003 with a
speed survey dated April 24, 2003. Based on the requirements contained in the
California Manual on Uniform Traffic Control Devices (MUTCD) and the California
Vehicle Code (CVC), this Engineering and Traffic Survey is considered expired and a
new Engineering and Traffic Survey is required.
SETTING SPEED LIMITS:
Effective July 1, 2009, Caltrans Division Chief Robert Copp signed the Policy Directive
to establish the procedure for setting speed limits in California. The changes for setting
speed limits are included in the California MUTCD pursuant to authority granted to
Cal trans in Section 21400 and 21401 of the California Vehicle Code.
The referenced directive clarifies procedures for setting speed limits. Caltrans has
incorporated two new standards into the CA MUTCD to help set speed limits in
California that are uniform, rational, enforceable by the police, and are supported by the
judicial system. Requirements of the new standards as established by Caltrans are:
• The speed limit shall be established at the nearest 5 mph increment of the 85 th
percentile.
• If the 5 mph reduction is applied, the Engineering and Traffic Survey shall
document in writing the conditions and justification for the reduced speed limit
and be approved by a registered Civil or Traffic Engineer.
In the City of Carlsbad, the predominant practice for managing speed is by legally
establishing a speed limit according to Caltrans criteria and then posting the speed limit
upon the road with regulatory signs. Police enforcement is used to target the most
egregious violators of the speed limit. A fundamental tenet is that laws are enacted to
protect the majority of the public by regulating the unsafe or unreasonable actions of the
few. When speed limits have been reasonably set, the enforcement efforts of the Carlsbad
Police Department are more effective.
Speed limits are established by law when the City Council adopts an ordinance and the
Page I
CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
COMMISSION MEETING OF:
( continued)
December 6, 2010 ITEMNO.6B
speed limit is posted on the roadway to indicate the maximum reasonable speed for a
driver to operate a vehicle under ideal conditions in off-peak free flowing conditions.
Among many factors, the three most persuasive arguments to consider when setting a
realistic, or rational, speed limit are:
1. 85th percentile speed ( critical speed)
2. Collision history
3. Conditions that may not be readily apparent to the driver
The 85th percentile speed, often referred to as the critical speed, is the speed which 85%
of the drivers are traveling at or below. The premise implied in speed zoning is that the
majority of drivers are operating their vehicles at or near the 85th percentile speed.
Drivers that operate their vehicle at speeds higher than the 85th percentile speed should be
the focus of the police as excessive speed is often a factor in a vehicle collision.
A comprehensive review of the collision history on a roadway also is an important
element in the process to establish a speed limit. In the collision analysis, factors such as
collision frequency, type, severity, road conditions, road geometry, lighting conditions,
and spatial distribution of the collisions are all considered. The review of collisions will
also reveal if there is a high incidence of speed-related collisions on the road at specific
locations. A number of collisions above the expected or normal threshold based upon
comparative collision rates may be an indicator of a potential for reducing collisions.
However, absent a significant collision history attributed to speed, it may be concluded
that drivers are operating their vehicle in a reasonable and prudent manner at the speed
they choose to drive.
Speed limits should not be lowered for conditions that are readily apparent to the driver
and the speed limit signs should not be used as intersection, curve or hazard warning
devices. For unusual conditions or conditions not readily apparent to motor vehicle
operators, appropriate warning signs can be installed.
In summary, through the use of engineering, educational, and enforcement techniques,
the management of vehicle speed is conducted. Voluntary public compliance with the
posted speed limit is the goal when determining a realistic prima facie speed limit to post
on a roadway. The realistic speed limit takes into consideration the normally competent
and careful actions of a reasonable driver and provides for the regulation of unreasonable
behavior by a few individuals. A posted speed limit should be readily accepted by drivers,
be fair and reasonable, be related to risk on the roadway, be determined by the majority of
drivers, and one that has a factual foundation. Posted speed limits reflect a balance of the
various factors specific to the roadway. As a result, roadway safety can be improved and
community concerns about traffic speed are appropriately and legally addressed.
Page2
CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
COMMISSION MEETING OF:
( continued)
December 6, 2010
BASIS OF ACTION:
ITEMN0.6B
The proposed speed limit for the road segment discussed in this report is regulated by
section 22357(a) of the California Vehicle Code: "Whenever a local authority determines
upon the basis of an engineering and traffic survey that a speed greater than 25 miles per
hour would facilitate the orderly movement of vehicular traffic and would be reasonable
and safe upon any street other than a state highway otherwise subject to a prima facie
limit of 25 miles per hour, the local authority may by ordinance determine and declare a
prima facie speed limit of 30, 35, 40, 45, 50, 55, or 60 miles per hour or a maximum
speed limit of 65 miles per hour, whichever is found most appropriate to facilitate the
orderly movement of traffic and is reasonable and safe. The declared prima facie or
maximwn speed limit shall be effective when appropriate signs giving notice thereof are
erected upon the street and shall not thereafter be revised except upon the basis of an
engineering and traffic survey. This section does not apply to any 25 mile per hour prima
facie limit which is applicable when passing a school building or the grounds thereof or
when passing a senior center or other facility primarily used by senior citizens."
DATA:
The subject portion of Loker Avenue West is approximately 0.69 miles in length and
functions as an industrial street located in an industrial park and features many closely-
spaced driveways on either side. The road follows a curvilinear alignment and has a
curb-to-curb width of 52 feet. There is a single lane of traffic in each direction separated
by a painted centerline. The subject segment has been improved with curb and gutter,
sidewalk and street lights on both sides of the roadway. On-street parallel parking is
allowed on the subject road segment. Traffic control on Loker Avenue West is provided
by a traffic signal at the intersection of Loker A venue West and Palomar Airport Road
and by two-way STOP control at Loker Avenue West and El Fuerte Street.
Traffic counts were obtained on Loker Avenue West on September 1, 2010 to determine
the two-way, 24-hour average daily traffic volume. The recent count data is indicated on
Table A.
TABLEA
24-HOUR TRAFFIC VOLUMES
e/o El Fuerte Street
Staff conducted ~eed surveys on Loker Avenue West on September 29, 2010 to
determine the 85 percentile speed. As stated previously, the 85th percentile speed,
commonly called the critical speed, is the speed at which 85 percent of the vehicles are
Page3
CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
COMMISSION MEETING OF:
( continued)
December 6, 20 I 0 ITEMNO.6B
traveling at or below. A sample of 100 vehicles was measured to calculate the 85th
percentile speed.
TABLED
SPEED SURVEY DATA
9/29/10 1,000' n/o Palomar Airport Rd. EB/WB 39 31 to 41 91%
9/29/10 1,165' w/o El Fuerte Street EB/WB 40 32 to 42 87%
The pace speed is the 10 mile per hour range of speeds that contain the highest number of
observed vehicles. Generally, the critical speed is in the upper range of the pace speed.
Staff reviewed the Police Department traffic collision reports for the two year period
from October 1, 2008 through September 30, 2010. There have been two reported
collisions on the subject segment of Loker Avenue West of which none were speed
related.
Since the California MUTCD requires that the speed limit be established at the nearest 5
mph increment of the 85th percentile and that no justification for a 5 mph reduction is
hereby presented, staff recommends that the speed limit be established at 40 miles per
hour.
Sections 22357 and 22358 of the California Vehicle Code authorize local authorities to
establish a prima facie speed limit on the basis of the results of an Engineering and
Traffic Survey. The Engineering and Traffic Survey considers such factors as the number
of collisions that have occurred on the road segment, roadway features, adjacent land
uses, driveway locations, traffic volumes, pedestrian volumes, critical speed, horizontal
and vertical alignment, stopping sight distance, and conditions that may not be readily
apparent to the driver.
RECOMMENDATION:
Based upon the results of the Engineering and Traffic Survey, the Traffic Safety
Coordinating Committee recommends revising the prima facie speed limit upon Loker
Avenue West, from Palomar Airport Road to El Fuerte Street, from 30 to 40 miles per
hour.
Page4
CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
COMMISSION MEETING OF:
( continued)
December 6, 2010
NECESSARY CITY COUNCIL ACTION:
ITEMNO.6B
An ordinance will be required to be adopted by the City Council to revise the prima facie
speed limit upon Loker Avenue West as recommended.
Page 5
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ENGINEERING AND TRAFFIC SURVEY
STREET: Loker Avenue West
LIMITS: Palomar Airport Road to El Fuerte Street
A. Prevailing Speed Data:
Date of Speed Survey
Location of Speed Survey
85th Percentile
10 MPH Pace
Percent in Pace
Posted S eed Limit On Date of Surve
B. Midblock Accident History:
(10/01/08 through 9/30/10)
Speed-Related Accidents
Total Accidents
Accidents/Million Vehicle Miles (MVM)
California Statewide Accidents/MVM
C. Traffic Factors:
Average Daily Traffic
Traffic Controls
Pedestrian/Bicycle Traffic
Bicycle Lanes
On-Street Parking
Other
D. Roadway Factors:
Circulation Element Street Classification
Length of Segment
Roadway Width
Number of Lanes
Vertical Alignment
Horizontal Alignment
Sidewalks
Driveways
Street Li htin
Direction: Eastbound/Westbound
9/29/10
1,000 feet n/o of Palomar Airport Road
39 MPH
31 to 41 MPH
91%
30MPH
0
2
0.63
Direction: Eastbound/Westbound
9/29/10
1,165 feet w/o of El Fuerte Street
40 MPH
32 to 42 MPH
87%
30MPH
1.71 (2007 State Rate for Same Type of Roadway)
8,508 -n/o Palomar Airport Road (9/01/10); 4,009 -w/o El Fuerte Street (9/01/10)
Stop Sign Control at El Fuerte Street; Traffic Signal at Palomar Airport Road
Heavy, on Occasion
No Designated Bicycle Lanes have been Striped on the Roadway
825 Feet of Parking Prohibited at South End (350 Feet on East and 475 Feet on West)
Bus Route
Unclassified
0.69 Mi.
52 Feet (Curb-to-Curb)
1 Lane Each Direction Except at South End Where 1 Through Lane and 1 Right-Turn-
Only Lane Exist
Relatively Flat
Curvilinear
Sidewalk on Each Side
Numerous Closely Spaced Driveways
Street Li hts on Each Side
E. Special Conditions: Roadway used by industrial park traffic, delivery trucks, and commuters. Travel lanes are separated by a
double-ellow centerline. Si ns warnin of edestrians crossin midblock are osted for motorists travelin in each direction.
F. Ad"acent Land Uses: Li ht Industrial, Commercial Retail, Delicatessen, USPS Mailbox, Bus Sto s
G. Remarks/Conditions Not Readily Apparent: Heavy pedestrian usage on occasion, especially during the noon lunch hour when
vehicles and pedestrians mix. During inclement weather, such as fog, visibility is reduced significantly. A large number of vehicles
park on the street near driveways which reduces the sight distance to and from the driveway. Travel lanes are separated by a
double-ellow centerline.
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 Caltrans Traffic Operations Policy Directive 09-04
effective July 1, 2009 and the California Manual on Uniform Traffic Control Devices with respect to design and prevailing speeds,
accident records, pedestrian and bicyclist safety, intersection and driveway spacing, and roadside and traffic conditions not readily
a arent to the driver. As eed limit ostin of 40 MPH is found to be a ro riate and ·ustified.
t • Approvals:
. : • . • . . . . : • . . :.· •• ••. . . • . . _::
o Recertification of existing speed zone per Sections 22357; 22358 and 40802 of the .California ·vehicle Code. D Establishment of new speed zone, • • • •
Approved_,:_...,.,..-....,.,.,.,,.,.,...------__,.....---....... -----
Trafflc Oivi$ipn Manager Date
CARCE5666T • ires 6/30/11
CITY OF CARLSBAD
SPEED SURVEY
DATE: 09/29/10 TIME: 1:15 PM TO 2:25 PM TOTAL VEHICLES:
WEATHER: Clear & Warm CRITICAL SPEED:
LOCATION: Loker Ave. West-1000' n/o Palomar Airport Rd. VEHICLES IN PACE:
OBSERVER/RECORDER: M. Rehfeldt ---------PACE SPEED(S):
30MPH
POSTED SPEED LIMIT
SOUTHBOUND
DIRECTION OF TRAVEL
MPH # % t# % %tile % #
65
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41 X X
40 X y X
39 X X
38 X X X X
37 X X X X
36 X X X X X X
35 X X X X X
34 X X X X X
33 X X X X
32 X X
31 X X
30 X X
29
28
27
26
25
24
23
22
21
2 4 5 5 100 6 3
4 8 8 8 95 8 4
3 6 5 5 87 4 2
5 10 11 11 82 12 6
6 12 12 12 71 12 6
7 14 13 13 59 12 6
6 12 12 12 46 12 6
6 12 11 11 34 10 5
5 10 8 8 23 6 3
2 4 6 6 15 8 4
2 4 5 5 9 6 3
2 4 4 4 4 4 2
Transportation Department
Traffic Division
100
39 • MPH _____ ..;;..;;.. ____ _
91 % -----------
31 TO 41 MPH -----
NORTHBOUND
DIRECTION OF TRAVEL
MPH
65
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
X X X 41
X X X X 40
X 39
X X X X 38
}l y X X 37
Jl X X 36
J[ X X 35
X X 34
X 33
X X 32
X X 31
X 30
29
28
27
26
25
24
23
22
21
DATE: 09/29/10 TIME: 9:25 AM
WEATHER: Clear & Warm
CITY OF CARLSBAD
SPEED SURVEY
TO 11:10 AM TOTAL VEHICLES:
CRITICAL SPEED:
LOCATION: Loker Ave. West~1165' w/o El Fuerte St. VEHICLES IN PACE:
OBSERVER/RECORDER: M. Rehfeldt _...;...;.;;_,;..;;...;.;;..;~----PACE SPEED(S):
30 MPH
POSTED SPEED LIMIT
WESTBOUND
DIRECTION OF TRAVEL
MPH # % E# % %tile % #
65
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44 X
43 X
42 X X
41 X X
40
39
38 X
37 X X X
36 y X X X
35 X y X
34 X X X
33 X X
32 X X
31
30
29
28
27
26
25
24
23
22
21
1 2 1 1 100
2 4 3 3 99 2 1
3 6 5 5 96 4 2
3 6 6 6 91 6 3
4 8 8 8 85 8 4
4 8 6 6 77 4 2
5 10 10 10 71 10 5
6 12 13 13 61 14 7
6 12 12 12 48 12 6
5 10 9 9 36 8 4
5 10 10 10 27 10 5
3 6 6 6 17 6 3
3 6 7 7 11 8 4
2 2 4 4 2
2 2 2 4 2
Transportation Department
Traffic Division
100
40 MPH _____ ...;..;. ____ _
87 % -----------
32 TO 42 MPH ----
EASTBOUND
DIRECTION OF TRAVEL
MPH
65
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44 -y 43
)( X 42
X X X 41 -x X X 40
X' 39
X X X X 38
X X y X y X 37
X X X X X X 36
X X X 35
X X X X 34
y X 33
X X X 32
X y 31
X y 30
29
28
27
26
25
24
23
22
21