Loading...
HomeMy WebLinkAbout2008-08-04; Traffic Safety Commission; ; Establish a prima facie speed limit upon Faraday Avenue from Orion Street to the east city limit( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: August 4, 2008 LOCATION: INITIATED BY: Faraday A venue, Orion Street to east city limit City Engineer ITEMNO. 6A REQUESTED ACTION: Establish a prima facie speed limit upon Faraday Avenue from Orion Street to the east city limit. BACKGROUND: Faraday Avenue (see Exhibit 1) is a secondary arterial traversing through the industrial park of Carlsbad Oaks North and is located north of and parallel to Palomar Airport Road. This portion of Faraday Avenue opened to traffic in October 2007. Immediately after opening the road, the Police Chief requested that speed limit signs be installed. As a result, 40 mile per hour speed limit signs were installed in both directions of Faraday A venue between Orion Street and the east city limit. 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: August 4, 2008 ( continued) ITEMNO. 6A 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 85 th 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. ( ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEE'FING OF: August 4, 2008 ( continued) ITEMNO. 6A 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. 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. ( ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: August 4, 2008 ( continued) ITEMNO. 6A 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. BASIS OF ACTION: 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." ( ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: August 4, 2008 ( continued) DATA: ITEMNO. 6A Faraday Avenue is striped with two traffic lanes in each direction and was constructed 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 1.35 miles in length. Faraday A venue has a curb-to-curb width of 64 feet. A bicycle lane is provided on both sides of the subject segment of Faraday A venue and the traffic lanes are separated by a striped median. At its intersection with El Fuerte Street, Faraday Avenue is controlled with a traffic signal. At its intersection with Orion Street, Faraday Avenue is also controlled by a traffic signal. Two additional traffic signals are located on Faraday Avenue, one at Whiptail Loop West and the other at Whiptail Loop East. Faraday Avenue follows a curvilinear alignment and has roadway grades that vary between 2% and 10%. Based upon traffic counts obtained on March 6, 2008, two-way total traffic volumes on Faraday Avenue range between 9,871 and 10,330 vehicles per day. The directional distribution of traffic volumes on Faraday Avenue is provided in Table A. DATE 3/06/08 3/06/08 TABLE A 24-HOUR TRAFFIC VOLUMES FARADAY AVENUE LOCATION E/B Orion Street to El Fuerte Street 4,981 Whiptail Loop East to east city limit 5,364 24-HOURADT " W/B TOTAL 4,890 9,871 4,966 10,330 Engineering Department design standards have a specified minimum horizontal radius of 670 feet for a secondary arterial. Within the subject curvilinear alignment of Faraday Avenue, there are a number of horizontal curves. The centerline horizontal radius for these curves ranges from 670 feet to a maximum of 1,250 feet. The larger radius curves are located westerly of El Fuerte Street. Each horizontal curve easterly of El Fuerte Street has the minimum standard radius for a secondary arterial of 670 feet. The calculated design speed for the 670-foot radius curve is 44 miles per hour based upon the Caltrans Highway Design Manual criteria. The centerline radius of 1,250 feet has a calculated design speed of 61 miles per hour. ', ( ( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: August 4, 2008 ITEMNO. 6A ( continued) There has been one reported collision on this segment of Faraday A venue since it opened to traffic and the police report attributes the primary collision factor as an improper turn that resulted in the driver running off the road. The collision history on this segment of Faraday Avenue, although there is less than 12 months of statistics, supports the recommended 45 mile per hour prima facie speed limit. The posted prima facie speed limit on Faraday A venue west of Orion Street is 40 miles per hour. This speed zone continues westerly to Cannon Road. 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: August 4, 2008 ( continued) ITEMNO. 6A Staff completed the Engineering and Traffic Survey ( attached) for the road segment of Faraday Avenue from Orion Street to the east city limit. The speed survey results contained within the Engineering and Traffic Survey are summarized in Table B. Three speed surveys were performed on February 28, 2008 in locations where prevailing speeds are representative of driver behavior in the proposed speed zone. 2/28/08 2/28/08 2/28/08 TABLEB SPEEDSURVEYDATAFORFARADAY AVENUE 350' w/o El Fuerte Street EB/WB 48 800' e/o Whiptail Loop West EB/WB 50 750' e/o Whiptail Loop East EB/WB 46 40-50 87 42-52 87 38-48 87 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 Faraday A venue from Orion Street to the east city limit. 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 within the subject segment of Faraday Avenue, as recommended. -$ NOT TO SCALE LEGEND: @ TRAFFIC SIGNAL PROJECT NAME ( LOCATION MAP I ,. I I iii I \ CITY OF CARLSBAD CITY OF VISTA tAIHIPTAIL LOOP vv WEST PROPOSED SPEED ZONE PROPOSED SPEED ZONE FOR A PORTION OF FARADAY A VENUE DRAKN BY: SCOTT EVANS, CARLSBAD ENGINEERING DEPT. 7/21/08 C: \TRAFFlC\SPEED ZONES\SPEED ZONE-FARADAY AVE: EAST.DWG EXHIBIT 1 ( CITY OF CARLSBAD ( ENGINEERING AND TRAFFIC SURVEY STREET: Faraday Avenue LIMITS: Orion Street to East City Limit 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: (10/05/07 through 5/31/08) Speed-Related Accidents Total Accidents Direction: Eastbound/Westbound 2/28/08 350 Feet w/o El Fuerte Street 48MPH 40 to 50 MPH 87% 40MPH Direction: Eastbound/Westbound 2/28/08 800 Feet e/o Whiptail Loop West 50MPH 42 to 52 MPH 87% 40MPH Direction: Eastbound/Westbound 2/28/08 750 Feet e/o Whiptail Loop East 46 MPH 38 to 48 MPH 87% 40MPH (New Roadway; Opened to Traffic on October 5, 2007) None 1 Accidents/Million Vehicle Miles (MVM) California Statewide Accidents/MVM 0.31 1.90 2005 State Rate for 4 or More Divided Lanes C. Traffic Factors: Average Daily Traffic Traffic Controls Pedestrian/Bicycle Traffic Bicycle Lanes On-Street Parking Other D. Roadway Factors: 9,871 -West of El Fuerte Street (3/06/08); 10,330 -at East City Limit (3/06/08) Traffic Signals at Orion Street, El Fuerte Street, Whiptail Loop (E), and Whiptail Loop (W) Light Bicycle Lane on Each Side Except Easterly 500 Feet of Segment Parking Prohibited on Each Side Bike Route er Circulation Element of the General Plan; Truck Route Circulation Element Street Classification Length of Segment Secondary Arterial 1.35 Mi. Roadway Width Number of Lanes Vertical Alignment Horizontal Alignment Sidewalks Driveways Street Li htin E. S ecial Conditions: Travel lanes are se 64 Feet (Curb-to-Curb) 2 Lanes Each Direction Roadway Grades Vary from 2% to 10% Curvilinear Sidewalk on Each Side Six Driveways Street Lights on Each Side F. Adjacent Land Uses: Open Space, Vacant Industrial Lots, Light Industrial, Fire Station,· Police Station, Waste Collection/ Rec clin Center. G. Remarks/Conditions Not Readily Apparent: Larger radius horizontal curves exist west of El Fuerte Street than east of El Fuerte Street. 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 45 MPH is found to be appropriate and ·ustified. DATE: 2/28/08 TIME: 11:05AM TO WEA TH ER: Overcast & Cool CITY OF CARLSBAD SPEED SURVEY ( 11 :50 AM TOTAL VEHICLES: CRITICAL SPEED: LOCATION: Faraday Avenue~350' w/o El Fuerte Street VEHICLES IN PACE: OBSERVER/RECORDER: J. Gale ---------PACE SPEED(S): 40 MPH POSTED SPEED LIMIT WESTBOUND DIRECTION OF TRAVEL MPH # % I:# % %tile % # 65 64 63 62 61 60 59 58 57 56 55 54 53 52 X 51 X 50 X 49 X X X X 48 X X X X 47 X X 46 X X X X X 45 X X X X X 44 X X X X X X 43 X 42 X X X X 41 X X X 40 X X X X X 39 X X X 38 37 X 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 1 2 1 1 100 1 2 2 2 99 2 1 1 2 1 1 97 4 8 7 7 96 6 3 4 8 5 5 89 2 1 2 4 7 7 84 10 5 5 10 6 6 77 2 1 5 10 8 8 71 6 3 6 12 12 12 63 12 6 1 2 10 10 51 18 9 5 10 12 12 41 14 7 4 8 11 11 29 14 7 6 12 9 9 18 6 3 4 8 6 6 9 4 2 1 1 3 2 1 1 2 2 2 2 2 1 Engineering Department Transportation Division 100 48 MPH _____ ....;..;;. ____ _ 87 % ----------- 40 TO 50 MPH EASTBOUND DIRECTION OF TRAVEL MPH 65 64 63 62 61 60 59 58 57 56 55 54 53 52 X 51 50 X X X 49 X 48 X X X X X 47 X 46 X X X 45 X X X X X X 44 X X X X X X X X 43 X X X X X X 42 X X X X X X 41 X X 40 X 39 X 38 X 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 ( DATE: 2/28/08 TIME: 1:25 PM TO CITY OF CARLSBAD SPEED SURVEY ( 1:50 PM TOTAL VEHICLES: WEATHER: Sunny & Mild CRITICAL SPEED: LOCATION: Faraday Avenue~ 800' e/o Whiptail Loop West VEHICLES IN PACE: OBSERVER/RECORDER: J. Gale PACE SPEED(S): --------- 40 MPH POSTED SPEED LIMIT WESTBOUND DIRECTION OF TRAVEL MPH # % 1: # % %tile % # 65 64 63 62 61 60 59 58 57 56 55 54 X 53 X 52 X 51 X X X X 50 X 49 X X X 48 X X X X X X 47 X X X X X X X X 46 X X X X 45 X 44 X X 43 X X X X 42 X X X X X 41 X X X 40 X X 39 -38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 1 2 1 1 100 1 2 1 1 99 2 4 4 4 98 4 2 5 10 5 5 94 2 4 6 6 89 8 4 4 8 5 5 83 2 1 6 12 9 9 78 6 3 8 16 11 11 69 6 3 4 8 7 7 58 6 3 1 2 11 11 51 20 10 2 4 12 12 40 20 10 4 8 12 12 28 16 8 5 10 9 9 16 8 4 3 6 3 3 7 2 4 3 3 4 2 1 1 1 1 2 1 Engineering Department Transportation Division 100 50 MPH _____ ....;;..;;. ____ _ 87 % ___ ..;___....:....;_ ____ _ 42 TO 52 MPH ---------- EASTBOUND DIRECTION OF TRAVEL MPH 65 64 63 62 61 60 59 58 57 56 55 54 53 X X 52 51 X X X X 50 X 49 X X X 48 X X 47 X X 46 X X X X X X X X X 45 X X X X X X X X X 44 X X X X X X X X 43 X X X X 42 41 X 40 X 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 ( DATE: 2/28/08 TIME: 10:10 AM TO WEATHER: Sunny & Mild CITY OF CARLSBAD SPEED SURVEY 10:55 AM TOTAL VEHICLES: CRITICAL SPEED: LOCATION: Faraday Avenue~750' e/o Whiptail Loop East VEHICLES IN PACE: OBSERVER/RECORDER: J. Gale ---------PACE SPEED(S): 40 MPH POSTED SPEED LIMIT EASTBOUND DIRECTION OF TRAVEL MPH # % E # % %tile % # 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 X 50 49 X 48 X 47 X X 46 X X 45 X X X X X X 44 X X X X 43 X X X 42 X X X 41 X X X X X X X X 40 X X X X 39 X X X X 38 X X X X X X X X 37 X 36 X 35 34 X 33 32 31 30 29 28 27 26 25 24 23 22 21 100 1 2 1 1 100 1 1 99 2 1 1 2 2 2 98 2 1 1 2 2 2 96 .2 1 2 4 4 4 94 4 2 2 4 7 7 90 10 5 6 12 11 11 83 10 5 4 8 8 8 72 8 4 3 6 8 8 64 10 5 3 6 9 9 56 12 6 8 16 12 12 47 8 4 4 8 8 8 35 8 4 4 8 7 7 27 6 3 8 16 13 13 20 10 5 1 2 2 2 7 2 1 1 2 3 3 5 4 2 2 1 2 2 2 2 2 1 Engineering Department Transportation Division 100 46 MPH ----------- 87 % ----------- 38 TO 48 MPH ----- WESTBOUND DIRECTION OF TRAVEL MPH 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 X 50 X 49 X 48 X X 47 X X X X X 46 X X X X X 45 X X X X 44 X X X X X 43 X X X X X X 42 X X X X 41 X X X X 40 X X X 39 X X X X X 38 X 37 X X 36 35 X 34 33 32 31 30 29 28 27 26 25 24 23 22 21