HomeMy WebLinkAbout2006-11-06; Traffic Safety Commission; ; Establish a prima facie speed limit upon Palomar Oaks Way from Palomar Airport Road to its northerly terminus( (
CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
COMMISSION MEETING OF: November 6, 2006 ITEMNO.6B
LOCATION: Palomar Oaks Way, Palomar Airport Road to its northerly terminus
INITIATED BY: Dannette Hess, 2006 Palomar Airport Road, Carlsbad, CA 92011
REQUESTED ACTION: Establish a prima facie speed limit upon Palomar Oaks Way from
Palomar Airport Road to its northerly terminus.
BACKGROUND:
Palomar Oaks Way, an industrial street, was constructed with the Airport Business Center
industrial park about 20 years ago. No northerly extension of the road is planned from its
current terminus point located north of Dryden Place.
SETTING SPEED LIMITS:
Optimal mobility is enhanced and overall traffic flow improved when drivers are
operating their vehicles at a speed that is reasonable and safe. In fact, the premise of CVC
section 22350, Basic Speed Law, is that no person shall drive ·upon a road at a speed
greater than is reasonable and prudent taking into account weather, visibility, and traffic
on the road and in no event at a speed that endangers the safety of others. Most drivers
operate vehicles in a reasonable manner. Traffic laws established on the basis of the
behavior of the reasonable and prudent motorist are found to be the most successful.
Roads in Carlsbad are designed in accordance with engineering standards to satisfy the
goals of a safe roadway and to enhance efficient traffic flow. One way to achieve the
goals is to establish proper and reasonable speed limits that can be enforced. Speed limits
that are reasonable can help to achieve voluntary compliance by the majority of drivers
without need for the presence of a police officer. Laws and/or the establishment of speed
zones that arbitrarily restrict travel by the majority of motorists can lead to wholesale
violations of the posted speed limit.
In the City of Carlsbad, the predominant practice for managing speed is by legally
establishing a prima facie speed limit and then posting the speed limit upon the road with
regulatory signs. A prima facie speed limit recognizes that conditions change throughout
the day and there is no one safe speed for all the conditions that may be present upon the
roadway. 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.
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CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
COMMISSION MEETING OF: November 26, 2006
( continued)
ITEMNO. 6B
Nationally recognized vetted practices and guidance per standards and procedures in the
Federal Highway Administration's national Manual on Uniform Traffic Control Devices
2003 Edition are considered when setting speed limits. In California, this manual is titled
the California Manual on Uniform Traffic Control Devices. The most common method of
establishing speed limits incorporates traffic engineering principles and other factors,
such as using the results of a speed survey, into the Traffic and Engineering Survey.
Prima facie speed limits are established by law when the City Council adopts an
ordinance and the 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. Critical speed (85th percentile speed)
2. Collision history
3. Conditions that may not be readily apparent to the driver
The premise implied in sgeed zoning is that the majority of drivers are operating their
vehicles at or near the 85t percentile speed. Drivers that operate their vehicle at speeds
higher than the 85th percentile speed should be the focus of the police. An important speed
zoning concept is that the disparity in speed between vehicles on the road is reduced
when prima facie speed limits are established at or near the 85th percentile speed and,
as a result, safety is enhanced. Also, a speed limit that is established based upon the
85th percentile speed will increase driver respect for the speed limit sign. Only those signs
that have the respect of the roadway user will have a positive effect to control traffic.
A review of the collision history on a roadway is an important element in the process to
establish a speed limit. The review will reveal if there is a high incidence of speed-related
collisions on the road at specific locations. Absent a significant collision history
attributed to speed, it can be concluded that drivers are operating their vehicle in a
reasonable and prudent manner at the speed they chose to drive.
The installation of a speed limit sign does not automatically decrease accident rates nor
increase roadway safety. Speed limits should not be lowered for conditions that are
readily apparent and the speed limit signs are not used as intersection, curve or hazard
warning devices. For the unusual conditions or conditions not readily apparent to drivers,
appropriate warning signs are installed.
Design factors such as the geometric elements of the road, sight distance, or other factors
may have a significant impact on the free flowing speed chosen by drivers. This driver
chosen speed, in turn, is considered when establishing a prima facie speed limit.
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CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
COMMISSION MEETING OF: November 6, 2006
( continued)
ITEMNO. 6B
A number of factors may be considered when establishing a prima facie speed limit.
The California Manual on Uniform Traffic Control Devices lists such factors as:
A. Road characteristics, shoulder condition, grade, alignment, and sight distance;
B. The pace speed;
C. Roadside development and pedestrian activity; and
D. Reported crash experience for at least a 12-month period.
As stated, basic speed law requires drivers to operate their vehicle at a speed that takes
into account all roadway factors, environmental elements, adjacent land uses, and other
traffic on the road. These are, in general, all readily apparent factors. W aming signs
placed on the roadway can alert drivers to the presence of an unseen or unanticipated
condition. As a result, drivers can operate their vehicle in a reasonable and prudent
manner by adjusting speed for the condition that may be encountered.
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 establish.
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 1isk on the roadway, be determined by the majority of drivers,
and one that has a factual foundation.
DATA:
Palomar Oaks Way is a public, industrial street located north of Palomar Airport Road.
Beginning about 200 feet south of Palomar Airport Road, Palomar Oaks Way is a private
street.
Between Palomar Airport Road and Wright Place, the road is striped with two
southbound traffic lanes and one northbound traffic lane. A single southbound left-tum
lane on Palomar Oaks Way serves the industrial park at the signalized intersection of
Palomar Airport Road and Palomar Oaks Way.
Traffic counts were obtained on July 19, 2006 on Palomar Oaks Way northerly of
Palomar Airport Road to determine the representative volumes on this street. The 24-hour
two-way traffic volume was 4,816 vehicles as indicated on Table A below. There is no
ADT design range for an industrial street in the City of Carlsbad Street Design Criteria
due to the variability of traffic volumes on industrial streets.
TABLE A
24-HOUR TRAFFIC VOLUMES
PALOMAR OAKS WAY
DATE
7/19/06 North of Palomar 4,816
CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
COMMISSION MEETING OF: November 6, 2006
( continued)
ITEMNO. 6B
Palomar Oaks Way terminates about 430 feet northerly of Dryden Place where a wooden
barricade is constructed. The length of Palomar Oaks Way from Palomar Airport Road to
its terminus is about 0.45 miles. Palomar Oaks Way is uncontrolled where three streets
intersect the road in a T-intersection configuration.
Staff conducted a speed survey on Palomar Oaks Way on October 3, 2006 to obtain data
to calculate the critical speed of vehicles. The critical speed, commonly called the
85 th percentile speed, is the free flowing speed at which 85 percent of the vehicles are
traveling at or below. A sample of 100 vehicles was measured to calculate the critical
speed. The critical speed is an important factor required to be considered in the
Engineering and Traffic Survey evaluation to establish the appropriate prima facie speed
to post upon a roadway.
The 85th percentile speed has been determined throughout the United States to generally
conform to a safe and reasonable speed limit. The California Manual on Uniform Traffic
Control Devices (FHW A's MUTCD 2003 Revision 1, as amended for use in California)
provides guidance when a speed limit is to be posted. It states that " .. .it should be
established at the nearest 10 km/h or 5 mph increment of the 85 th percentile speed of
free-flowing traffic". As an option, the California MUTCD states that "The posted speed
limit maXi be reduced by 10 km/h (5 mph) from the nearest 10 km/h or 5 mph increment
of the 85 h percentile speed, where engineering study indicates the need for a reduction in
speed to match existing conditions with the traffic safety needs of the community".
California Vehicle Code section 627 defines the term "Engineering and Traffic Survey"
and lists its requirements, as follows:
627. (a) "Engineering and traffic survey," as used in this code, means a survey of highway
and traffic conditions in accordance with methods determined by the Department of
Transportation for use by state and local authorities.
(b) An engineering and traffic survey shall include, among other requirements
deemed necessary by the department, consideration of all of the following:
(1) Prevailing speeds as determined by traffic engineering measurements.
(2) Accident reports.
(3) Highway, traffic, and roadside conditions not readily apparent to the driver.
( c) When conducting an engineering and traffic survey, local authorities, in
addition to the factors set forth in paragraphs (1) to (3), inclusive, of subdivision (b) may
consider all of the following:
(1) Residential density, if any of the following conditions exist on the particular
portion of highway and the property contiguous thereto, other than a business district;
(A) Upon one side of the 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.
(B) Upon both sides of the highway, collectively, within a distance of a quarter of a
mile, the contiguous property fronting thereon is occupied by 16 or more separate
dwelling houses or business structures.
(C) The portion of highway is longer than one-quarter of a mile but has the ratio of
separate dwelling houses or business structures to the length of the highway described in
either subparagraph (A) or (B).
(2) Pedestrian and bicyclist safety.
(
CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
COMMISSION MEETING OF: November 6, 2006
( continued)
ITEMNO. 6B
Staff completed the Engineering and Traffic Survey (attached) for Palomar Oaks Way
from Palomar Airport Road to its northerly terminus. Results of the speed survey,
contained within the Engineering and Traffic Survey that was conducted on
Palomar Oaks Way, are summarized in Table B.
TABLEB
SPEED SURVEY DATA FOR PALOMAR OAKS WAY
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 located in the upper range of the pace
speed.
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.
There have been no reported collisions on Palomar Oaks Way for the period September 1,
2004 through August 31, 2006.
RECOMMENDATION:
Upon review of the results of the Engineering and Traffic Survey, the Traffic Safety
Coordinating Committee recommends establishing a 35 mile per hour prima facie speed
limit upon Palomar Oaks Way from Palomar Airport Road to its northerly terminus.
NECESSARY CITY COUNCIL ACTION:
An ordinance will be required to be adopted by the City Council to establish the 35 mile
per hour prima facie speed limit upon Palomar Oaks Way, as recommended.
PROPOSED
SPEED ZONE
NOT TO SCALE
PROJECT NAME
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LOCATION MAP
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VIDA ROBLE CAMINO
LEGEND:
($) TRAFFIC SIGNAL
PROPOSED SPEED ZONE
PALOMAR OAKS WAY
EXHIBIT
1
DRAM/ BY: SCOTT £VANS, CARLSBAD £NG/NffRING DEPT. 10/5/06 C: \ TRAffiC\SP££D ZON£S\SPffD ZONE-PALOMAR OAKS WA Y.DIIG
( CITY OF CARLSBAD (
ENGINEERING AND TRAFFIC SURVEY
STREET: Palomar Oaks Way l-
LIMITS: Northerly Terminus to Palomar Airport Road
A. Prevailing Speed Data:
Date of Speed Survey
Location of Speed Survey
85th Percentile
10 MPH Pace
Percent in Pace
Posted S eed Limit
B. Midblock Accident History:
(9/01/04 through 8/31/06)
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:
Street Classification
Length of Segment
Roadway Width
Number of Lanes
Vertical Alignment
Horizontal Alignment
Sidewalks
Driveways
Street Li htin
None
None
N.A.
Direction: Northbound/Southbound
10/03/06
At Wright Place
37 MPH
29 to 39-MPH
81% .
No Posted S eed Limit
1.89 (2004 Rate for Same Type of Roadway)
4,816 -North of Palomar Airport Road (7/19/06)
Traffic Signal at Palomar Airport Road
Light
No Designated Bicycle Lanes Have Been Striped on the Roadway
Parking Prohibited on Both Sides •
Bus Route
Unclassified
0.45Mi.
52 Feet (Curb-to-Curb)
Two Southbound Lanes South of Wright Place; One Lane Each Direction Elsewhere
Roadway Grades Vary from 1.39% to 7%
Curvilinear
Sidewalk on Each Side
Seven Driveways
Street Lights on Each Side
E. Special Conditions: Travel lanes are separated by a double-yellow centerline between Wright Place and Palomar Airport Road.
Roadwa used b industrial ark traffic, delive trucks, and commuters
F. Adjacent Land Uses: Office buildings, golf course maintenance facility, three USPS mail boxes, storage facility, and electric utility
easements. •
G. Remarks/Conditions Not Readily Apparent: Vehicles stop along the east curb tine just south of Camino Vida Roble to deposit
mail in three USPS mailboxes located there.
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
for Streets and Highways (FHWA's MUTCD 2003 Edition, as amended for use in California) with respect to design and prevailing
speeds, accident records, pedestrian and bicyclist safety, intersection and driveway spacing, and roadside and traffic conditions
not readil a arent to the driver. A s eed limit ostin of 35 MPH is found to be a ro riate and ·ustified. :'t:-;;.::::--;:-.c-c.
DATE: 10/03/06 TIME: 10:05 AM TO
WEATHER: Sunny & Mild
CITY OF CARLSBAD
SPEED SURV6Y
(
11 :25 AM TOTAL VEHICLES:
CRITICAL SPEED:
LOCATION: Palomar Oaks Way at Wright Place
OBSERVER/RECORDER: • J. Gale .....;.. _______ _
VEHICLES IN PACE:
PACE SPEED(S):
NONE
POSTED SPEED LIMIT
NORTHBOUND
DIRECTION OF TRAVEL
MPH # % I:# % %tile % #
65
64
63
62
61
60
59
58
57
56
55
54
53
52
51
50
49
4B
47
46
45
44
43
42 X
41 '
40 X
39 X
38 X
37 X X X
36 X X X X X X
35 X
34 X X X X X X X X
33 X X X X X
32 X X X
31 X X X X X
30 X X X X X X
29 X X X X
28 X X
27 X
26 X X
25
24
23
22
21
1 2 1 1 100
99
1 2 3 3 99 4 2
1 2 4 4 96 6 3
1 2 4 4 92 6 3
3 6 7 7 88 8 4
6 12 8 8 81 4 2
1 2 5 5 73 8 4
8 16 11 11 68 6 3
5 10 11 11 57 12 6
3 6 7 7 46 8 4
5 10 9 9 39 8 4
6 12 11 11 30 10 5
4 8 8 8 19 8 4
2 4 3 3 11 2 1
1 2 5 5 8 8 4
2 4 3 3 3 2 1
Engineering Department
Transportation Division
100
37 MPH ------=------
81 % _____ .....:...;. ____ _
29 TO 39 MPH ----------
SOUTHBOUND
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
41
X X 40
X X X 39
X X X 38
X X X X 37
X X 36
X X X X 35
X X X 34
X X X X X X 33
X X X X 32
X X X X 31
X X X X X 30
X X X X 29
X 28
X X X X 27
X 26
25
24
23
22
21