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Home My WebLink About2008-03-03; Traffic Safety Commission; ; Establish a prima facie speed limit upon Eagle Drive from Palomar Airport Road to its intersection with Lionshead AvenueCITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: March 3, 2008 LOCATION: INITIATED BY: Eagle Drive, Palomar Airport Road to Lionshead A venue City Engineer ITEMNO. 6C REQUESTED ACTION: Establish a prima facie speed limit upon Eagle Drive from Palomar Airport Road to its intersection with Lionshead A venue. BACKGROUND: Eagle Drive (see Exhibit 1) is an industrial street located in the Palomar Forum industrial park north of Palomar Airport Road. The road opened to traffic in the later portion of 2006. 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. ( ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: March 3, 2008 ( continued) ITEMNO. 6C 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 sgeed 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 85th 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. ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: March 3, 2008 ( continued) DATA: ITEMNO. 6C Eagle Drive has one traffic lane in each direction and is built to city standards with curb and gutter, sidewalks, and street lights. The road is not classified on the Circulation Element of the General Plan and is 0.27 miles in length. Eagle Drive has a curb-to-curb width of 52 feet, which is the Carlsbad standard for an industrial road. A bicycle lane is provided on both sides of Eagle Drive, resulting in on-street parking being prohibited on each side of the road. At its terminus with Lionshead A venue, Eagle Drive is controlled by a stop sign. At the Palomar Airport Road intersection, Eagle Drive is controlled by a traffic signal. Two cul-de-sac roads that intersect Eagle Drive and four driveways located on Eagle Drive provide access to industrial lots. The lots have existing buildings constructed with some future construction to take place. Eagle Drive has a curvilinear alignment with roadway grades that vary between 5.67% and 8.0%. Based upon traffic counts obtained in January 2008, two-way total traffic volumes on Eagle Drive is a low 478 vehicles. The directional distribution of traffic volumes on Eagle Drive is indicated in Table A. TABLE A 24-HOUR TRAFFIC VOLUMES EAGLE DRIVE •· 24-HOUR ADT S/B TOTAL 209 478 There have been no reported collisions on Eagle Drive from when the road opened and ending December 31, 2007. 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 (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 85thpercentile 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)." ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: March 3, 2008 ( continued) ITEMNO. 6C 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. Staff completed the Engineering and Traffic Survey ( attached) for Eagle Drive from Palomar Airport Road to Lionshead Avenue. The speed survey results contained within the Engineering and Traffic Survey prepared for Eagle Drive are summarized in Table B. TABLED SPEED SURVEY DATA FOR EAGLE DRIVE 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. ( ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: March 3, 2008 ( continued) RECOMMENDATION: ITEMNO. 6C Based upon 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 Eagle Drive from Palomar Airport Road to Lionshead A venue. 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 Eagle Drive, as recommended. LOCATION CITY OF VISTA ------+----CITY OF CARL-SB_A_D _____ _ NOT TO SCALE PROPOSED SPEED ZONE ( MAP LEGEND: ® TRAFFIC SIGNAL ~ STOP SIGN PROJECT NAME PROPOSED SPEED ZONE FOR EAGLE DRIVE DRAVtN BY: SCOTT EVANS, CARLSBAD ENGINEERING DEPT. 2 ti 08 C: TRAFFIC SPEED ZONES\SPEED ZONE-EAGLE DRIVE.DWG EXHIBIT 1 ( CITY OF CARLSBAD ( EI\IGINEERING AND TRAFFIC SUt<VEY STREET: Eagle Drive LIMITS: Lionshead 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 B. Midblock Accident History: (1/01/06 through 12/31/07) 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 Parkin D. Roadway Factors: Circulation Element Street Classification Length of Segment Roadway Width Number of Lanes Vertical Alignment Horizontal Alignment Sidewalks Driveways Street Lighting Direction: Northbound/Southbound 1/10/08 160 Feet n/o Tiger Run Court 37 MPH 28 to 38 MPH 82% No Posted S eed Limit None None None 1.81 (2005 State Rate for Same Type of Roadway) 478 -North of Grey Hawk Court (1/09/08) Stop Sign Control at Lionshead Avenue; Traffic Signal at Palomar Airport Road Liaht Bicycle Lane on Each Side Parking Prohibited on Each Side Unclassified 0.27 Mi. 52 Feet (Curb-to-Curb) One Lane Each Direction Roadway Grades Vary from 5.67% to 8% Curvilinear Sidewalk on Each Side Four Driveways Street Li hts on Each Side E. Special Conditions: Travel lanes are separated by a two-way left-turn lane. F. Adjacent Land Uses: Light industrial, vacant industrial lots. G. Remarks/Conditions Not Readily Apparent: Eagle Drive provides access to the Carlsbad Raceway Business Park. 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, pedestrian and bicyclist safety, intersection and driveway spacing, and roadside and traffic conditions not readily apparent to the driver. A speed limit posting of 35 MPH is found to 'be appropriate and ·ustified. CITY OF CARLSBAD SPEED SURVEY DATE: 01/15/08 TIME: 8:30 AM TO 11 :05 AM TOTAL VEHICLES: WEATHER: Clear & Cool CRITICAL SPEED: --------------- LOCAT10 N: Eagle Drive~160' n/o Tiger Run Court VEHICLES IN PACE: OBSERVER/RECORDER: M. Rehfeldt ---------PACE SPEED(S): NONE POSTED SPEED LIMIT NORTHBOUND 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 43 42 X 41 X 40 39 38 37 X 36 X X X 35 X X X X 34 X 33 X X X X 32 X X 31 X X X 30 X 29 X 28 X 27 X 26 X 25 24 23 22 21 1 4 2 4 100 4 1 1 4 1 2 96 2 4 94 8 2 2 4 90 8 2 86 1 4 3 6 86 8 2 3 12 5 10 80 8 2 4 16 5 10 70 4 1 1 4 4 8 60 12 3 4 16 7 14 52 12 3 2 8 4 8 38 8 2 3 12 6 12 30 12 3 1 4 3 6 18 8 2 1 4 2 4 12 4 1 1 4 2 4 8 4 1 1 4 1 2 4 1 4 1 2 2 Engineering Department Traffic Operations Section 50 37 MPH 82 % ----------,---- 28 TO 38 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 X 42 41 X X 40 X X 39 38 X X 37 X X 36 X 35 X X X 34 X X X 33 X X 32 X X X 31 X X 30 X 29 X 28 27 26 25 24 23 22 21