HomeMy WebLinkAbout2008-07-07; Traffic Safety Commission; ; Establish a prima facie speed limit upon El Fuerte Street from Palomar Airport Road to its intersection with Faraday Avenue( (
CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
.COMMISSION MEETING OF: July 7, 2008
LOCATION:
INITIATED BY:
El Fuerte Street, Palomar Airport Road to Faraday Avenue
City Engineer
ITEMNO. 6B
REQUESTED ACTION: Establish a prima facie speed limit upon El Fuerte Street from
Palomar Airport Road to its intersection with Faraday A venue.
BACKGROUND:
El Fuerte Street (see Exhibit 1) is a secondary arterial located in the industrial parks of
Carlsbad Airport Business Center and Carlsbad Oaks North north of Palomar Airport
Road. The northerly portion of the road between Loker A venue East/West opened to
traffic in February 2008.
SETTING SPEED LIMITS:
Optimal mobility is enhanced and overall traffic flow improved when drivers are
operating their vehicles at a speed that is reasonable, comfortable, convenient, and safe
under the existing conditions. It is generally acknowledged that the control of speed can
be a significant factor in influencing and improving roadway safety by reducing the
number of collisions. 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.
Driver behavior is an extension of social attitudes and most drivers operate their vehicles
in a reasonable manner. This is demonstrated by their good driving records.
Therefore, traffic laws established on the basis of the behavior of the reasonable and
prudent motorist are found to be the most successful. As a result, speed limits that are
considered credible and enforceable will help enhance traffic safety and the operating
efficiency on the roadway and achieve driver compliance.
Roads in Carlsbad are designed in accordance with engineering standards to satisfy the
goals of having a safe roadway, provide mobility, offer mode choices, and to enhance
efficient traffic flow. One way that these goals are achieved is by establishing 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. For a speed limit to be considered effective, drivers must believe that the posted
speed limit is safe, properly established, and legally enforceable.
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CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
COMMISSION MEETING OF: July 7, 2008
( continued)
ITEMNO. 6B
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. When law enforcement officers
and the courts have confidence that speed limits have been set on a reasonable basis, their
enforcement efforts are more effective.
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 sReed zoning is that the majority of drivers are operating their
vehicles at or near the 85 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. In addition, a speed limit that is established based upon the
85 th percentile speed will increase driver respect for the speed limit sign. Only those
regulatory or warning signs that have the respect of the roadway user will have a positive
effect to control driver behavior traffic.
A comprehensive review of the collision history on a roadway 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 Caltrans
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 chose to
drive.
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CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
COMMISSION MEETING OF: July 7, 2008
( continued)
ITEMNO. 6B
The installation of a speed limit sign will not automatically decrease accident rates nor
increase roadway safety. Speed limits should not be lowered for conditions that are
readily apparent to the driver 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 motor vehicle operators, appropriate warning signs are installed.
Design factors, including the geometric elements of the road, sight distance, or other
factors such as adjacent land uses, parking, or pedestrian activity, 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.
A number of factors may be considered when establishing a prima facie speed limit.
The 2003 MUTCD lists such factors as:
A. Road characteristics, shoulder condition, grade, alignment, and stopping sight
distance;
B. The pace speed;
C. Roadside development and activity; and
D. Reported crash experience for at least a 12-month period.
Other factors are included, as appropriate, in the Engineering and Traffic Survey that
becomes the basis for establishing the prima facie speed limit. Among the requirements to
be considered are residential density, and pedestrian and bicycle safety. Other factors
include superelevations, profile conditions, intersection spacing and offsets, commercial
driveways, and pedestrians in the roadway where sidewalks do not exist.
Basic speed law as stipulated in the California Vehicle Code 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 to the driver. Warning 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 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.
( (
CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
COMMISSION MEETING OF: July 7, 2008
( continued)
DATA:
ITEMNO. 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
maximum 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.''
El Fuerte Street has two traffic lanes in each direction and is built to city standards with
curb and gutter, sidewalks, and street lights. The road is classified on the Circulation
Element of the General Plan as a secondary arterial and is 0. 72 miles in length. El Fuerte
Street has a curb-to-curb width of 82 feet from Palomar Airport Road to Loker A venue
East/West and continues northerly from that intersection with a curb-to-curb width of
62 feet.
A bicycle lane is provided on both sides of El Fuerte Street only between Loker A venue
East/West and Faraday Avenue. At its terminus with Faraday Avenue, El Fuerte Street is
controlled with a traffic signal. At its intersection with Palomar Airport Road, El Fuerte
Street is also controlled by a traffic signal. The road segments of Loker A venue
East/West are controlled by stop signs. At the Loker Avenue East/West intersection,
El Fuerte Street is uncontrolled.
El Fuerte Street has a curvilinear alignment with roadway grades that vary between 2%
and 10%. Based upon traffic counts obtained on April 9, 2008, two-way total traffic
volumes on El Fuerte Street are 4,975 vehicles per day north of Palomar Airport Road
and 2,475 vehicles per day south of Faraday A venue .. The directional distribution of
traffic volumes on El Fuerte Street is provided in Table A.
DATE
4/09/08
4/09/08
TABLE A
24-HOUR TRAFFIC VOLUMES
EL FUERTE STREET
N/lf
2,375
200' South of Farada A venue 1,330
.SIB
2,600 4,975
1,145 2,475
( (
CITY OF CARLSBAD
TRAFFIC SAFETY COMMISSION
STAFF REPORT
COMMISSION MEETING OF: July 7, 2008 ITEMNO. 6B
( continued)
There has been one reported collision on this segment of El Fuerte Street from
May 1, 2006 through April 30, 2008. However, it should be noted that the segment of
El Fuerte Street northerly of the Loker A venue East/West intersection opened to traffic in
February 2008. The collision history supports the recommended 45 mile per hour prima
facie speed limit.
Critical speeds, also known as the 85th percentile speeds, have been determined
throughout the United States to generally conform to a safe and reasonable speed limit.
The California Manual on Uniform Traffic Control Devices (FHWA's MUTCD 2003
Revision 1, as amended for use in California) provides guidance when a speed limit is to
be posted. It states that "the speed limit should be established at the nearest 10 km/h
(5 mph) increment to the 85th percentile speed. However, in matching existing conditions
with the traffic safety needs of the community, engineering judgment may indicate the
need for a further reduction of 10 km/h (5 mph)."
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: July 7, 2008
( continued)
ITEMNO. 6B
Staff completed the Engineering and Traffic Survey (attached) for El Fuerte Street from
Palomar Airport Road to Faraday Avenue. The speed survey results contained within the
Engineering and Traffic Survey are summarized in Table B. One speed survey was
performed on April 2, 2008 where prevailing speeds are representative of this proposed
speed zone section.
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.
RECOMMENDATION:
Based upon the results of the Engineering and Traffic Survey, the Traffic Safety
Coordinating Committee recommends establishing a 45 mile per hour prima facie speed
limit upon El Fuerte Street from Palomar Airport Road to Faraday A venue.
NECESSARY CITY COUNCIL ACTION:
An ordinance will be required to be adopted by the City Council to establish the 45 mile
per hour prima facie speed limit upon the subject segment of El Fuerte Street, as
recommended.
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NOT TO SCALE
PROJECT NAME
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LOCATION MAP
LEGEND:
@ EXISTING TRAFFIC SIGNAL
PROPOSED SPEED ZONE
EL FUERTE STREET
DRAVtN BY: SCOTT EVANS, CARLSBAD ENGINEERING DEPT. 6 17 08 C: TRAFFIC SPEED ZONES SPEED ZONE-EL FUERTE: STREET--2.DWG
PROPOSED
SPEED ZONE
AIRPORT
EXHIBIT
1
( CITY OF CARLSBAD (
ENGINEERING AND TRAFFIC SURVEY
STREET: El Fuerte Street
LIMITS: Faraday Avenue 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
8. Midblock Accident History:
(5/01/06 through 4/30/08)
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: Northbound/Southbound
4/02/08
300 Feet n/o Loker Avenue
43 MPH
35 to 45 MPH
90%
No Posted S eed Limit
0
1
0.51
1.90 2005 State Rate for Same T e of Roadwa
2,475 -s/o Faraday Avenue (4/09/08); 4,975 -n/o Palomar Airport Road (4/09/08)
Traffic Signals at Faraday Avenue and Palomar Airport Road
Light
Bicycle Lane on Each Side between Faraday Avenue and Loker Avenue
Parking Prohibited on Each Side
Not a Truck Route
Secondary Arterial
0.72 Mi.
64 Feet -Faraday Avenue to Loker Avenue; 82 feet -Loker Avenue to Palomar Airport Road
Two Lanes Each Direction
Roadway Grades vary from 2% to 10%
Curvilinear
Sidewalk on Each Side
Four Driveways
Street Li hts on Each Side
E. Special Conditions: Roadway is used by industrial park traffic, delivery trucks and commuters. Lane lines are offset at the
intersection of Loker Avenue East/West.
F. Ad'acent Land Uses: Li ht industrial, sewer lift station, bic cle
G. Remarks/Conditions Not Readily Apparent: An asphalt bicycle path, 1 O feet wide, is located on the west side of the roadway
just outside of the public right-of-way. It begins at Loker Avenue and continues 425 feet to the north where it terminates.
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
with respect to design and prevailing speeds, accident records, pedestria1:f and bicyclist safety, intersection and driveway spacing,
and roadside and traffic conditions not readily apparent to the driver. A speed limit posting of 45 MPH is found to be appropriate
and ·ustified.
----------1.(
DATE: 04/02/08 TIME: 8:55 AM TO
WEATHER: Clear & Cool
CITY OF CARLSBAD
SPEED SURVEY
10:35 AM TOTAL VEHICLES:
CRITICAL SPEED: ---------------
LOCATION: El Fuerte Street ~300' n/o Loker Avenue VEHICLES IN PACE:
OBSERVER/RECORDER: M. Rehfeldt ---------PACE SPEED(S):
NONE
POSTED SPEED LIMIT
SOUTHBOUND
DIRECTION OF TRAVEL
MPH # % t # % %tile % #
65
64
63 I
62
61
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46 X
45 X X
44 X X X X X
43 X X X X X
42 X X X X X
41 X X X X X X X
40 X X X X X
39 X X X X X
38 X X X X X X X
37 X X
36 X X X
35 X X
34 X
33
32
31
30
29
28
27
26
25
24
23
22
21
1 2 1 1 100
2 4 5 5 99 6 3
5 10 6 6 94 2 1
5 10 8 8 88 6 3
5 10 8 8 80 6 3
7 14 13 13 72 12 6
5 10 12 12 59 14 7
5 10 11 11 47 12 6
7 14 11 11 36 8 4
2 4 7 7 25 10 5
3 6 8 8 18 10 5
2 4 6 6 10 8 4
1 2 3 3 4 4 2
1 1 1 2 1
Engineering Department
Transportation Division
100
43 MPH --------=--=------
90 % -----------
35 TO 45 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
X X X 45
X 44
X X X 43
X X X 42
X X X X X X 41
X X X X X X X 40
X X X X X X 39
X X X X 38
X X X X X 37
X X X X X 36
X X X X 35
X X 34
X 33
32
31
30
29
28
27
26
25
24
23
22
21