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Home My WebLink About2007-02-05; Traffic Safety Commission; ; Establish a prima facie speed limit upon Dove Lane from Moorhen Place to El Camino Real( ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: February 5, 2007 LOCATION: Dove Lane, Moorhen Place to El Camino Real INITIATED BY: Deputy City Engineer, Transportation Division ITEMNO.6A REQUESTED ACTION: Establish a prima facie speed limit upon Dove Lane from Moorhen Place to El Camino Real BACKGROUND: No prima facie speed limit is established on Dove Lane west of El Camino Real. The road was extended to a residential subdivision located westerly of the Dove Library approximately seven years ago. 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. ( ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: February 5, 2007 (continued) ITEMNO. 6A 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 (85 th 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 85 th 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 85 th 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 tum, is considered when establishing a prima facie speed limit. ( \. CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: February 5, 2007 (continued) ITEMNO. 6A A number of factors may be considered when establishing a prima facie speed limit. The 2003 MlJTCD lists such factors as: A. Road characteristics, shoulder condition, grade, alignment, and sight distance; B. The pace speed; C. Roadside development and 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. 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 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 risk on the roadway, be determined by the majority of drivers, and one that has a factual foundation. DATA: The subject p01tion of Dove Lane is a two-lane road westerly of El Camino Real that serves the Dove Library, shopping center, and single-family residential units. It is unclassified in the Circulation Element of the General Plan. The road varies in width between 40 and 48 feet, is 0.28 miles in length and has three intersecting driveways. The driveways serve the entrance to the shopping center from Dove Lane, the Dove Library, and a single-family home located easterly of Moorhen Place. Centerline striping has been installed on Dove Lane between El Camino Real and the Dove Library driveway. Sidewalks are constructed on each side of Dove Lane for pedestrian access to the shopping center and Dove Library. The commercial shopping center generates traffic to uses such as a movie theater, restaurants, grocery store, and small retail shops. A future 53-unit residential development, named La Costa Village Center Townhomes, will be constructed on the northerly side of Dove Lane near El Camino Real. This project will have driveway access on Dove Lane across from the Dove Library driveway. Dove Lane is controlled with a traffic signal at El Camino Real. At its intersection with Moohren Place, Dove Lane is controlled with a stop sign. ·( ( ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: February 5, 2007 ITEMNO. 6A ( continued) Traffic volumes range from 7,533 vehicles per day west of El Camino Real to 359 vehicles per day east of Moorhen Place based upon counts taken on January 9, 2007, as shown on Table A. TABLE A 24-HOUR TRAFFIC VOLUMES DOVELANE 1/09/07 w/o El Camino Real 1/09/07 e/o Moorhen Place 24-FIOWADT · 3,921 7,533 181 359 Dove Lane follows a relatively straight alignment and has two horizontal curves west of El Camino Real. These curves have a centerline radius of 406 feet near El Camino Real and 800 feet near Moorhen Place. Roadway grades vary between 2% and 10%. On-street parallel parking is prohibited from a point about 65 feet west of the Dove Library driveway to El Camino Real on both sides of the road. 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 "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; ( ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: February 5, 2007 (continued) ITEMNO. 6A (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 Dove Lane from Moorhen Place to El Camino Real. Results of the speed survey, contained within the Engineering and Traffic Survey that was conducted on Dove Lane, are summarized in Table B. TABLEB SPEED SURVEY DATA FOR DOVE LANE 1/10/07 400' e/o Moorhen Place EB/WB 39 31-41 32-42 33-43 90 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 numqer 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 the subject segment of Dove Lane between December 1, 2004 and November 30, 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 Dove Lane from Moorhen Place to El Camino Real. 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 Dove Lane, as recommended. ( LOCATION s"'1t--'( ~t~~~ NOT TO SCALE LEGEND: @ TRAFFIC SIGNAL ~ STOP SIGN ( MAP PROPOSED SPEED ZONE -,:,Orn z (/)-\ ,B~ I \-\Z. \ ~~ I I z_-\ I I :I:.o /~ Vi PROJECT NAME DOVE LANE PROPOSED SPEED ZONE DRAIIN BY: SCOTT EVANS, CARLSBAD ENGINEERING DEPT. 1/25/07 C: \ TRAfflC\SPEED ZONES\SPEED ZONE-DO'vf: LANE.DWG Gj EXHIBIT 1 STREET: Dove Lane CITY OF CARLSBAD ENGINEERING AND TRAFFIC SURVEY LIMITS: Moorhen Place to El Camino Real 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: (12/01/04 through 11/30/06) Speed-Related Accidents Total Accidents Accidents/Million Vehicle Miles (MVM) California Statewide Accidents/MVM C. Traffic Factors: Direction: Eastbound/Westbound . 1/10/07 400 Feet e/o Moorhen Place 39MPH 31 to 41, 32 to 42 , 33 to 43 MPH 90% No Posted S eed Limit None None None 1.89 (2004 Rate for Same Type of Roadway) Average Daily Traffic Traffic Controls Pedestrian/Bicycle Traffic Bicycle Lanes 7,533 -West of El Camino Real {1/09/07); 359 -East of Moorhen Place (1/09/07) Traffic Signal at El Camino Real; Stop Sign Control at Moorhen Place Light On-Street Parkin Striped Bicycle Lane on Each Side Between El Camino Real and Shopping Genier Driveway Parking Allowed Only Within West Half of Segment D. Roadway Factors: Circulation Element Street Classification Length of Segment Roadway Width Number of Lanes Vertical Alignment Horizontal Alignment Sidewalks Driveways Street Lighting Unclassified 0.28 Mi. Varies Between 40 Feet and 48 Feet One Lane Each Direction Roadway Grades Vary from 2% to 10% Relatively Straight Except for One 406-Foot Radius Curve and One 800-Foot Radius Curve Sidewalk on Each Side Three Driveways Limited Street Li htin E. S ecial Conditions: Travel lanes are stri ed on easter! 625 feet of se ment. F. Adjacent Land Uses: Single-family residential, open space, commercial shoppirig center including bank and theater, public libra . • G. Remarks/Conditions Not Readil A arent: Pedestrian activit due to adjacent sho in center, bank, library, and theater. 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 Revision 1, 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. Appropriate speed survey(s) is/are attached hereto and made a part hereof. DATE: 1/10/07 TIME: 12:55 PM WEATHER: Overcast & Mild TO ( CITY OF CARLSBAD SPEED SURVEY 3:50 PM TOTAL VEHICLES: CRITICAL SPEED: LOCATION: Dove Lane~400' e/o Moorhen Place VEHICLES IN PACE: OBSERVER/RECORDER: J. Gale WESTBOUND 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 41 X 40 X X 39 X X X 38 X 37 X X X X 36 X X X X X 35 X X 34 33 X X X X X 32 31 X 30 29 28 27 26 25 24 23 22 21 PACE SPEED(S): NONE POSTED SPEED LIMIT # % L # % %tile % # 1 4 2 4 100 4 1 1 4 1 2 96 2 8 4 8 94 8 2 3 12 6 12 86 12 3 1 4 5 10 74 16 4 4 16 6 12 64 8 2 5 20 10 20 52 20 5 2 8 3 6 32 4 1 2 4 26 8 2 5 20 6 12 22 4 1 2 .4 10 8 2 1 4 1 2 6 1 2 4 4 1 2 1 2 2 4 1 Engineering Department Transportation Division 50 39 MPH 90 % 31 TO 41 MPH 32 TO 42 MPH 33 TO ~3 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 43 X 42 41 X X 40 X X X 39 X X X X 38 X X 37 X X X X X 36 X 35 X X 34 X 33 X X 32 31 X 30 29 X 28 27 ,26 25 24 23 22 21