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HomeMy WebLinkAbout2010-08-02; Traffic Safety Commission; ; Revise the prima facie speed limit upon Batiquitos Drive from Golden Star Lane to Aviara Parkway,- ' CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: August 2, 20 I 0 ITEM NO. 6B LOCATION: INITIATED BY: Batiquitos Drive, Golden Star Lane to Aviara Parkway Bob Johnson REQUESTED ACTION: Revise the prima facie speed limit upon Batiquitos Drive from Golden Star Lane to Aviara Parkway. BACKGROUND: Batiquitos Drive from Golden Star Lane to Aviara Parkway features one lane in each direction and is divided by a painted median (see Exhibit 1). Batiquitos Drive serves residential developments and also provides access to the Aviara Golf Club. SETTING SPEED LIMITS: Effective July 1, 2009, Caltrans Division Chief Robert Copp signed the Policy Directive to establish the procedure for setting speed limits in California. The changes for setting speed limits are included in the California Manual on Uniform Traffic Control Devices (CA MUTCD) pursuant to authority granted to Caltrans in Section 21400 and 21401 of the California Vehicle Code (CVC). Caltrans recognizes that the setting of speed limits can be controversial. However, if speed limits are established arbitrarily low, the majority of drivers would be violators of the speed limit, public confidence would be low, and roadway users (drivers) would not respect the traffic control device (speed limit sign). The referenced directive clarifies procedures for setting speed limits. Caltrans has incorporated two new standards into the CA MUTCD to help set speed limits in California that are uniform, rational, enforceable by the police, and are supported by the judicial system. Requirements of the new standards as established by Caltrans are: • The speed limit shall be established at the nearest 5 mph increment of the 85th percentile. • If the 5 mph reduction is applied, the Engineering and Traffic Survey shall document in writing the conditions and justification for the reduced speed limit and be approved by a registered Civil or Traffic Engineer. The 85th percentile speed, often referred to as the critical speed, is the speed which 85% of the drivers are traveling at or below. 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 Page 1 C CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: ( continued) August 2, 2010 ITEM NO. 6B 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. Unfortunately, good judgment is not used by all operators of a motor vehicle. 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 even though their capabilities and limitations of the vehicle operators vary greatly. 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. In the City of Carlsbad, the predominant practice for managing speed is by legally establishing a prima facie speed limit according to Caltrans criteria 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, the enforcement efforts of the Carlsbad Police Department 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 and the latest revision thereof is used to set speed limits in California. 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 Engineering and Traffic Survey. Prima facie speed limits are established by law when the City Council adopts an ordinance and the speed Page 2 ~ CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: ( continued) August 2, 2010 ITEMNO.6B 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 as excessive speed is often a factor in a vehicle collision. 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 also 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 choose to drive. 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 unusual conditions or conditions not readily apparent to motor vehicle operators, appropriate warning signs can be 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 tum, is considered when establishing a prima facie speed limit. A number of other factors may be considered when establishing a prima facie speed limit. The CA MUTCD lists such factors as: Page 3 ~ CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: ( continued) August 2, 2010 ITEMNO.6B 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. 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, enviromnental 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, 3 5, 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 Page4 CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: ( continued) August 2, 2010 ITEMN0.6B 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." DATA: Batiquitos Drive from Golden Star Lane to A viara Parkway is unclassified in the Circulation Element of the General Plan and functions as a collector street. This portion of the roadway is 1.06 miles in length and has a curb to curb width of 48 feet. The traffic lane in each direction is separated by a painted median. The subject segment of Batiquitos Drive from Golden Star Lane to Aviara Parkway features concrete curb and gutter, sidewalk, bicycle lanes, and street lights on both sides of the roadway. The subject segment is curvilinear and centerline vertical grades range from 1% to 7.94%. Parking is not allowed on this segment of Batiquitos Drive. The subject segment of Batiquitos Drive is currently posted at 35 miles per hour based on the Engineering and Traffic Survey dated May 4, 2006. Traffic counts were obtained at two locations on Batiquitos Drive on April 28, 2010 to determine the two-way, 24-hour average daily traffic volume. The recent count data is indicated on Table A. TABLEA 24-HOUR TRAFFIC VOLUMES Batiquitos Drive from Golden Star Lane to Aviara Parkway 4/28/10 East of Aviara Drive 1,978 l, 722 3,700 4/28/10 South of Aviara Parkway 1,551 1,392 2,943 Staff conducted a speed survey on Batiquitos Drive on June 30, 20 IO to determine the critical speed of vehicles. As stated previously, the critical speed, commonly called the 85th percentile, is the speed at which 85 percent of the vehicles are traveling at or below. A sample of 100 vehicles was measured to calculate the critical speed. The critical speed is an important factor used to help determine the appropriate prima facie speed to post upon a roadway. 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 (MUTCD) provides guidance when a speed limit is to be posted. Page 5 CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: ( continued) August 2, 20 I 0 TABLED ITEMN0.6B SPEED SURVEY DATA FOR BATI UITOSDRIVE Ditection 6/30/10 At Hummingbird Road NB/SB 39 ,,,:~e-· 31-41 .-.:· .·· ·%in 'ha. 89 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 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. Staff reviewed the Police Department collision reports for the two year period from May 1, 2008 through April 30, 2010. There has been one speed-related collision reported on the subject segment. RECOMMENDATION: Based upon the results of the Engineering and Traffic Survey, the Traffic Safety Coordinating Committee recommends revising the prima facie speed limit upon Batiquitos Drive from Golden Star Lane to A viara Parkway from 35 to 40 miles per hour. 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 Batiquitos Drive from Golden Star Lane to A viara Parkway, as recommended. Page6 LOCATION MAP ~ NOT TO SCALE ~ ------------- PROPOSED SPEED ZONE t- PROPOSED SPEED ZONE FOR BATIQUITOS DRIVE FROM GOLDEN STAR LANE TO AVIARA PARKWAY I I I I I I I l I I t EXHIBIT l 1 I _________________________________ .._ ___ Ji! STREET: Batiguitos Drive CITY OF CARLSBAD ENGINEERING AND TRAFFIC SURVEY LIMITS: Golden Star Lane to Aviara Parkway A. Date of Speed Survey Location of Speed Survey 85th Percentile 10 MPH Pace Percent in Pace Posted S eed Limit 8. Midblock Accident History: (5/01/08 through 4/30/10) Speed-Related Accidents Total Accidents Accidents/Million Vehicle Miles (MVM) California Statewide Accidents/MVM C. Traffic Factors: 6/30/10 At Hummingbird Road ·39 MPH 31 to 41 MPH 89% 35MPH 1 1 0.39 1. 71 (2007 State Rate for Same T pe of Roadway) Average Daily Traffic Traffic Controls Pedestrian/Bicycle T raffle Bicycle Lanes 3,700-East of Aviara Drive (4/28/10); 2,943 -South of Aviara Parkway (4/28/10) Traffic Signal at Aviara Parkway On-Street Parkin D. Roadway Factors: Light Bicycle Lane on Each Side Parkin Prohibited on Each Side Circulation Element Street Classification Collector with modified design criteria Length of Segment 1.06 Mi. Roadway Width 48 Feet (Curb-to-Curb) Number of Lanes 1 lane Each Direction Vertical Alignment Roadway Grades Vary from 1 % to 7.94% Horizontal Alignment Curvilinear Sidewalks Sidewalk on Each Side Driveways Two Driveways Street Lighting Street Lights on Each Side E. Special Conditions: This section of Batiquitos Drive provides access to Aviara Golf Club and Argyle Restaurant. The road also serves as access to view points and trail heads along Batiquitos Lagoon. An intersection warning sign is posted for northbound motorists approaching Hummingbird Road. Advance warning signs and signs with an advisory speed lower than the posted speed limit have been posted for southbound motorists approaching a curve in the roadway east of the southerly intersection and a roachin the intersection at S oonbill Lane souther! intersection . G. Remarks/Conditions Not Readily Apparent: Several golf carts cross Batiquitos Drive at A:-iiara Drive adjacent to the golf course entrance. The road and sidewalk is used by joggers and other pedestrians. Advanced warning signs are posted for each direction informin motorists of destrians crossin the roadwa ad·acent to Aviara Drive. 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 Caltrans Traffic Operations Policy Directive 09-04 Effective July 1, 2009 and 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 a arent to the driver .. A s eed limit stin of 40 MPH is found to be a ro riate and ·ustified. I. A1ipfo1ials: - ~::i1i!::i1.:::::tln1::=:~n.e•pef-,Se~tions-.223~7;:22a,~ 'and•-40802;.~ith~:•~~~hia:\le~tcleCo~e. • • ' Approved NOTE: Appropriate speed survey(s) is /are attached hereto and made a part hereof. -t>~te J~s6730(11 0 DATE: 06/30/10 TIME: 9:45 AM WEATHER: Cloudt & Cool TO CITY OF CARLSBAD SPEED SURVEY 10:50AM TOT AL VEHICLES: CRITICAL SPEED: LOCATION: Batiquitos Drive at Hummingbird Road VEHICLES IN PACE: OBSERVER/RECORDER: M. Rehfeldt SOUTHBOUND DIRECTION OF TRAVEL MPH 65 64 63 62 61 60 59 56 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 X 40 39 X 38 X X 37 36 X X 35 X X 34 X 33 X 32 X X 31 X 30 X 29 28 27 26 25 24 23 22 21 PACE SPEED(S): 35 MPH POSTED SPEED LIMIT # % E # % %tile % # 1 1 100 2 1 1 2 3 3 99 4 2 3 6 4 4 96 2 1 2 4 4 4 92 4 2 4 8 8 8 86 8 4 5 10 11 11 80 12 6 3 6 7 7 69 8 4 6 12 13 13 62 14 7 6 12 12 12 49 12 6 5 10 10 10 37 10 5 5 10 9 9 27 8 4 4 8 9 9 18 10 5 3 6 6 6 9 6 3 2 4 2 2 3 1 2 1 1 1 Transportation Department Traffic Division 100 39 MPH 89 % 31 TO 41 MPH NORTHBOUND DIRECTION OF TRAVEL MPH 65 64 63 62 61 60 59 56 57 56 55 54 53 52 51 50 49 48 47 46 45 44 X 43 X X 42 X 41 X 40 X X X 39 X X X X X 38 X X X 37 X X X X X 36 X X X 35 X X 34 X 33 X X 32 X X 31 30 29 28 27 26 25 24 23 22 21