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HomeMy WebLinkAbout2007-11-05; Traffic Safety Commission; ; Revise the prima facie speed limit upon Marron Road from El Camino Real to the city limits at Highway 78 (State Route 78)( ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: November 5, 2007 ITEMNO.6C LOCATION: Marron Road, El Camino Real to north city limits at Highway 78 INITIATED BY: City Engineer REQUESTED ACTION: Revise the prima facie speed limit upon Marron Road from El Camino Real to the city limits at Highway 78 (State Route 78). BACKGROUND: The existing prima facie speed limit of 35 miles per hour on Marron Road from El Camino Real to the city limits at Highway 78 was established in-1983. Based upon the increase in the critical speeds on Marron Road over time, an examination of the appropriateness and need to raise the prima facie speed limit should be undertaken to comply with criteria in the California MUTCD. 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. It is generally acknowledged that the control of speed can be a significant factor in influencing and improving roadway safety. 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. 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 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. For a speed limit to be considered effective, drivers must believe that the posted speed limit is safe and proper. ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: November 5, 2007 ( 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 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. 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. ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: November 5, 2007 ( continued) ITEMNO. 6C 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. 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 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. Posted speed limits reflect a balance of the various factors specific to the roadway. As a result, roadway safety is improved and community concerns about traffic speed are addressed. ( ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: November 5, 2007 ( continued) DATA: ITEMNO. 6C Marron Road is classified on the Circulation Element of the General Plan as a secondary arterial. It has vertical grades that are generally flat and is a four-lane roadway that follows a curvilinear alignment through a commercial area of Carlsbad adjacent to the Westfield Shopping Center (former Plaza Camino Real). The road intersects at State Route 78 on the north and intersects to the east at El Camino Real, a signalized intersection. The portion of Marron Road located east of El Camino Real has a posted thirty-five mile per hour speed limit. The subject portion of Marron Road is 1.01 miles in length. Two streets, Monroe Street and Jefferson Street, intersect Marron Road in the northerly portion of the speed zone and each is controlled by a traffic signal. A traffic signal on the easterly portion of the road serves traffic exiting the shopping center at Cinema Way. Numerous driveways on Marron Road provide ingress and egress to the commercial business located adjacent to the road. Bicycle lanes are striped on each side of Marron Road. On-street parking is not allowed and for most of the subject road segment, sidewalks are provided for pedestrians. At Jefferson Street and continuing northerly, a raised center median has been constructed. The remainder of the road has a striped center median and left-tum lanes. Daily traffic volumes range from 8,973 vehicles on the easterly portion of the subject road segment to 21,967 vehicles on the westerly portion based upon traffic counts obtained in 2007 and 2006, respectively. The directional distribution of the traffic volumes is presented in Table A. DATE 4/18/06 8/29/07 TABLE A 24-HOUR TRAFFIC VOLUMES MARRONROAD LOCATION . NIB SIB E/B .. South of State Route 78 10,331 11,636 --- West of Cinema Way ------4,606 W/B TOTAL ---21,967 4,367 8,973 In the two-year period ending May 31, 2007, there were 18 reported traffic collisions in the subject road segment, eight of which were speed related. The accident rate per million vehicle miles on the subject portion of Marron Road is 1.58, which is lower than the statewide rate of 1.90, based upon a comparable roadway. Collisions are distributed throughout the road segment as shown on the Traffic Collision Summary, Exhibit 2. ( ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: November 5, 2007 ITEMNO. 6C ( continued) 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 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: November 5, 2007 ( continued) ITEMNO. 6C Staff completed the Engineering and Traffic Survey ( attached) for the segment of Marron Road from the city limits near Highway 78 to El Camino Real. Results of two speed surveys, contained within the Engineering and Traffic Survey prepared for Marron Road, are summarized in Table B. TABLEB SPEED SURVEY DATA FOR MARRON ROAD 900' w/o Cinema 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. RECOMMENDATION: Based upon the results of the Engineering and Traffic Survey, the Traffic Safety Coordinating Committee recommends raising the existing speed limit and establishing a 40 mile per hour prima facie speed limit upon Marron Road from the city limits near Highway 78 to El Camino Real. NECESSARY CITY COUNCIL ACTION: An ordinance will be required to be adopted by the City Council to establish the 40 mile per hour prima facie speed limit upon Marron Road, as recommended. .~ ~OT TO SCALE LEGEND: ® TRAFFIC SIGNAL ~ DRIVEWAY PROJECT NAME ( ( LOCATION MAP PROPOSED SPEED ZONE FOR MARRON ROAD DRAWN BY: SCOTT EVANS, CARLSBAD ENGINEERING DEPT. 9 IJ 07 C: 1RAmc SPEED ZONES SPEED ZONE-MARRON RD2.DWG ::c ~ ~ PROPOSED SPEED ZONE EXHIBIT 1 ( CITY OF CARLSBAD ENGINEERING AND TRAFFIC SURVEY ( STREET: Marron Road LIMITS: North City Limits at Highway 78 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: (6/01/05 through 5/31/07) 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 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 8/08/07 800' w/o Monroe Street 43MPH 36 to 46 MPH 90% 35 MPH 8 18 1.58 Direction: Eastbound/Westbound 8/08/07 900' w/o Cinema Way 44MPH 35 to 45 MPH 84% 35 MPH 1.90 (2005 Rate for 4 or More Divided Lanes) 21,967 -North of Jefferson Street (4/18/06); 8,973 -West of Cinema Way (8/29/07) Traffic Signals at El Camino Real, Cinema Way, Monroe Street and Jefferson Street Moderate Bicycle Lane on Each Side Parking Prohibited on Each Side Major Bus Route & Truck Route; Bike Route per Circulation Element of the General Plan Secondary Arterial 1.01 Mi. 64 Feet (Curb-to-Curb) 2 Lanes Each Direction Relatively Flat Curvilinear No Sidewalk on Portions of Roadway Numerous Commercial Driveways Limited Street Lighting E. Special Conditions: Slow moving buses utilize this roadway to and from the bus transfer station located at the west end of the Plaza Camino Real mall. F. A • Uses: Regional Shopping Center, Community Shopping Center, Theater, Bus Transfer Station, Local Park, La ical Reserve Hikin Trails G. Remarks/Conditions Not Readily Apparent: The curvilinear alignment limits visibility of some driveways. Pedestrians crossing at mid-block locations and hi h volumes of traffic are associated with the ad·acent sho in centers. ' 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 priveway spacing, and roadside and traffic conditions not readily apparent to the driver. A speed limit posting of 40 MPH is found to be appropriate and ·ustified. ( DATE: 08/08/07 TIME: 9:50 AM WEATHER: Clear & Warm TO ( CITY OF CARLSBAD SPEED SURVEY 10:30 AM TOTAL VEHICLES: CRITICAL SPEED: LOCATION: Marron Road ~800' w/o Monroe Street VEHICLES IN PACE: OBSERVER/RECORDER: M. Rehfeldt 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 X 45 X X 44 X X 43 X X X 42 X X X X X 41 X X X X X X 40 X X X X X 39 X X X X X X X 38 X X X X X X 37 X X X .. x X 36 X X X X X 35 X X 34 X 33 32 31 30 29 28 27 26 25 24 23 22 21 PACE SPEED(S): 35 MPH POSTED SPEED LIMIT # % L # % %tile % # 1 1 100 2 1 1 2 2 2 99 2 1 2 4 5 5 97 6 3 2 4 4 4 92 4 2 3 6 7 7 88 8 4 5 10 10 10 81 10 5 6 12 13 13 71 14 7 5 10 10 10 58 10 5 7 14 11 11 48 8 4 6 12 11 11 37 10 5 5 10 10 10 26 10 5 5 10 9 9 16 8 4 2 4 4 4 7 4 2 1 2 3 3 3 4 2 Engineering Department Transportation Division 100 43 MPH 90 % 36 TO 46 MPH EASTBOUND DIRECTION OF TRAVEL MPH 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 X 47 X 46 X X X 45 X X 44 X X X X 43 X X X X X 42 X X X X X X X 41 X X X X X 40 X X X X 39 X X X X X 38 X X X X X 37 X X X X 36 X X 35 X X 34 33 32 31 30 29 28 27 26 25 24 23 22 21 ( DATE: 08/08/07 TIME: 9:00 AM TO WEATHER: Clear & Warm ( CITY OF CARLSBAD SPEED SURVEY 9:40 AM TOTAL VEHICLES: CRITICAL SPEED: LOCATION: Marron Road ~900' w/o Cinema Way VEHICLES IN PACE: OBSERVER/RECORDER: M. Rehfeldt ---------PACE SPEED(S): 35 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 X 46 X X X 45 X X 44 X X X 43 X X 42 X X X X X X 41 X X X X X X 40 X X X X X X X 39 X X X X X 38 X X X X 37 X X X X X 36 X X 35 X X X 34 X 33 32 31 30 29 28 27 26 25 24 23 22 21 1 2 2 2 100 2 1 3 6 5 5 98 4 2 2 4 5 5 93 6 3 3 6 4 4 88 2 1 2 4 6 6 84 8 4 6 12 11 11 78 10 5 6 12 9 9 67 6 3 7 14 13 13 58 12 6 5 10 11 11 45 12 6 4 8 11 11 34 14 7 5 10 9 9 23 8 4 2 4 4 4 14 4 2 3 6 6 6 10 6 3 1 2 3 3 4 4 2 1 1 1 2 1 Engineering Department Transportation Division 100 44 MPH ---~------- 84 % 35 TO 45 MPH EASTBOUND DIRECTION OF TRAVEL MPH 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 X 47 X X 46 X X X 45 X 44 X X X X 43 X X X X X 42 X X X 41 X X X X X X 40 X X X X X X 39 X X X X X X X 38 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 LOCATION: ( MARRON ROAD (EL CAMINO REAL TO NORTH CITY LIMITS) TRAFFIC COLLISION SUMMARY CITY OF CARLSBAD TRANSPORTATION DIVISION BY: M. Rehfeldt PERIOD: DATE: 10-15-07 FROM: 6-1-05 TO: 5-31-07 NUMBER OF MIDBLOCK TRAFFIC COLLISIONS BY TYPE YEAR TOTAL PROPERTY INJURY FATAL LIGHT DARK WET DAMAGE 2005 10 6 4 0 6 4 0 2006 6 3 3 0 4 2 1 2007 2 1 1 0 2 0 0 NORTH CITY LIMITS G) 9-1-05 PDO ESS -H+R 6532 14:56 L EB-RE AREND 0 12-21-05 PDO FTC 9765 18: 22 D EB-REAREND ® 9-17-05 PDO UNR(RSS) 6945 12:26 L NB-BROADSIDE ® 12-22-05 INJ ESS-H+R(FOG) 9789 17:21 D NB-REAREND G) 9-23-05 PDO IT 71?6 13:19 L WB-BROADSIDE @ 12-23-05 INJ 1/RW 9813 12:01 L EB-HEAD ON © 12-09-05 PDO IT 9417 18:17 D WB-BROADSIDE ® 12-30-05 PDO IT 10020 23: 11 D NB-HIT OBJ. ® 12-17-05 INJ 1/RW 9669 16:07 L EB-BROADSIDE @ 5-26-06 . INJ ESS 4181 06:20 L SB-RE AREND © 12-21-05 INJ ESS-IT 9755 11: 00 L SB-REAR END @ 9-17-06 PDO ESS-INATT 7882 14:10 L SB-SIDESWIPE © 11-14-06 PDO ESS(Yi£T) 9695 12:00 L WB-REAREND 8 12-18-06 INJ ESS 10784 18:46 D WB-REAREND @ 12-20-06 PDO ESS 10849 17:53 D 'Ml-SIDESWIPE @ 12-28-06 INJ FTC 11038 15:12 L SB-RE AREND @ 4-24-07 INJ 1/RW 3655 18:16 L EB-BROADSIDE @ 5-04-07 PDO 1/RW 3989 17:20 L EB-BROADSIDE ~ NOT TO SCALE LEGEND CONST CONSTRUCTION H&R HIT & RUN M/C MOTORCYCLE ESS EXCEEDING SAFE SPEED ILC IMPROPER LANE CHANGE RSS RAN STOP /SIGNAL FTC FOLLOWING TOO CLOSE IP IMPROPER PASS 1/RW VIOLAlED R-0-W HBO HAD BEEN DRINKING INATT INA TlENTION ws l'IRONG SIDE COLLISION DATA DESCRIPTION 18 IMPROPER BACKING IT IMPROPER TURN DWI DRIVING WI-IILE INTOXICA lED (DATE) (RESULT) (COLL. FACTOR) IS IMPROPER START 0TH OTHER INJ INJURY (REP. #) (TIME/D=DARK-(DIR. OF TIRA \/EL-) PDO PROPERTY DAMAGE ONLY L=LIGHT) DESCRIPTION EXHIBIT 2