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Home My WebLink About2010-10-04; Traffic Safety Commission; ; Revise the prima facie speed limit upon Avenida Encinas, from Palomar Airport Road to 0.67 miles south of Palomar Airport Roadr CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: October 4, 2010 ITEMNO.6A LOCATION: INITIATED BY: Avenida Encinas from Palomar Airport Road to 0.67 miles south of Palomar Airport Road Traffic Division Manager REQUESTED ACTION: Revise the prima facie speed limit upon Avenida Encinas, from Palomar Airport Road to 0.67 miles south of Palomar Airport Road. BACKGROUND: Currently, this portion of Avenida Encinas is posted at 40 miles per hour. The Engineering and Traffic Survey on file was approved on May 5, 2003 with a speed survey dated April 8, 2003. Based on the requirements contained in the California Manual on Uniform Traffic Control Devices (MUTCD) and the California Vehicle Code (CVC), this Engineering and Traffic Survey is considered expired and a new Engineering and Traffic Survey is required. 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 MUTCD pursuant to authority granted to Caltrans in Section 21400 and 2140 I of the California Vehicle Code. 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 Cal trans are: • The speed limit shall be established at the nearest 5 mph increment of the 85 th 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 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 Page I CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: ( continued) October 4, 2010 ITEMNO.6A 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. These goals are achieved by establishing proper and reasonable speed limits that can be enforced. Speed limits that are reasonable result in 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 speed limits have been reasonably set, the enforcement efforts of the Carlsbad Police Department are more effective. 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. 85th percentile speed ( critical speed) 2. Collision history 3. Conditions that may not be readily apparent to the driver Page2 CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: ( continued) October 4, 20 I 0 ITEMNO.6A The premise implied in sfeed zoning is that the majority of drivers are operating their vehicles at or near the 851 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. 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 marmer 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 should not be 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. 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 Page 3 CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: ( continued) October 4, 2010 ITEMNO.6A 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." DATA: The subject portion of Avenida Encinas is approximately 0.67 miles in length and is classified as a secondary arterial in the Circulation Element of the General Plan. It is located adjacent to the railroad corridor, industrial buildings and the Encina Water Pollution Control facility. The road follows a relatively straight alignment and varies in width from 32 to 65 feet. The subject segment has been improved with curb and gutter, sidewalk and street lights on the entire east side the roadway. An asphalt concrete berm exists on the west side of the road. Approximately 1400 feet of roadway has been improved on the west side with curb and gutter and sidewalk. On-street parallel parking is allowed on some portions of the subject road segment. Traffic counts were obtained on Avenida Encinas on September 2, 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 Staff conducted speed surveys on A venida Encinas on August 26, 2010 to determine the 85th percentile speed. As stated previously, the 85th percentile speed, commonly called the critical speed, 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 85th percentile speed. TABLED SPEED SURVEY DATA FOR AVENIDA ENCINAS 8/26/10 0.3 mi s/o Palomar Airport Road NB/SB 44 36 to 46 86% 8/26/10 0.6 mi s/o Palomar Airport Road NB/SB 46 38 to 48 84% Page4 CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: ( continued) October 4, 2010 ITEMNO.6A 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. Staff reviewed the Police Department collision reports for the two year period from August 1, 2008 through July 31, 2010. There have been six reported collisions on the subject segment, one of which was speed-related. The collision rate of 1.31 accidents per million vehicle miles is lower than the 2007 state average of 1. 71 for the same type of roadway. Since the California MUTCD requires that the speed limit be established at the nearest 5 mph increment of the 85th percentile and that no justification for a 5 mph reduction is hereby presented, staff recommends that the speed limit be established at 45 miles per hour. 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 revising the prima facie speed limit upon Avenida Encinas, from Palomar Airport Road to 0.67 miles south of Palomar Airport Road, from 40 to 45 miles per hour. NECESSARY CITY COUNCIL ACTION: An ordinance will be required to be adopted by the City Council to revise the prima facie speed limit upon A venida Encinas as recommended. Page 5 PROPOSED 45MPH SPEED LIMIT NOT TO SCALE PROJECT NAME C LOCATION MAP RD. TRA~r---... srAJ~ \\ AVENIDA ENCINAS PROPOSED 45 MPH SPEED LIMIT EXHIBIT 1 CITY OF CARLSBAD ENGINEERING AND TRAFFIC SURVEY STREET: Avenida Encinas LIMITS: Palomar Airport Road to 0.67 mi. s/o 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: (8/01/08 through 07/31/10 Speed-Related Accidents Total Accidents 1 Direction: Northbound/Southbound 8/26/10 0.3 mi. s/o Palomar Airport Road 44MPH 36 to 46 MPH 86% 40MPH 6 1.31 Direction: Northbound/Southbound 8/26/10 0.6 mi. s/o Palomar Airport Road 46MPH 38 to 48 MPH 84% 40MPH Accidents/Million Vehicle Miles (MVM) California Statewide Accidents/MVM 1.71 (2007 State Rate for Same Type of Roadway) C. Traffic Factors: Average Daily Traffic Traffic Controls Pedestrian/Bicycle Traffic Bicycle Lanes On-Street Parking Other D. Roadway Factors: 9,385 -South of Palomar Airport Road (9/02/10) Traffic Signal at Palomar Airport Road Light - No Designated Bicycle Lanes Have Been Striped on the Roadway Parking Allowed on approximately 30% of East Side and 40% of West Side Bike Route per Circulation Element of the General Plan; Bus Route Circulation Element Street Classification Secondary Arterial Length of Segment 0.67 mi. Roadway Width 32 to 65 Feet Number of Lanes One Lane Each Direction Vertical Alignment Relatively Flat Horizontal Alignment Relatively Straight Sidewalks Sidewalk on Entire East Side and approximately 1,422 Feet of West Side Driveways Numerous Closely Spaced Driveways on East Side Street Li htin Street Lights on East Side Only E. Special Conditions: Except for the northerly 1/10 mile and southerly 0.27 mile of this segment, the roadway is unimproved and narrows to 32 feet between the two ends. The entire east side is improved with curb, gutter and sidewalk. Travel lanes are se arated b either a double-ellow centerline or ainted median. F. Adjacent Land Uses: Water Recycling Facility, Wastewater Treatment Plant, Service Station, Light Industrial, Office Buildings, Railroad Corridor G. Remarks/Conditions Not Readil A arent: N/A. 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. As eed limit ostin of 45 MPH is found to be a ro riate and ·ustified. • 1 Apptovals: . . .,, . . ,. . □. B •.•. ecert,ifica.Uo·n·of.exis. t. ii1,.~.,.$p. ~!:l·d. zb ... ne pe(Sections 22357; i2:3-58 :ahd 408Q2 of the • C:~lifgfhi a Vehicl~ God!:}. [9"'Estabhshment ofnewspeedzqoe; • . •··.••· .. •• • • . •··•·•···· . •• •>· • • NOTE: Appropriate speed survey(s) is /are attached hereto and made a part hereof. CITY OF CARLSBAD SPEED SURVEY DATE: 08/26/10 TIME: 8:35 AM TO 9:00AM TOTAL VEHICLES: WEATHER: Clear & Warm CRITICAL SPEED: LOCATION: Avenida Enclnas-0.3 mi s/o Palomar Airport Road VEHICLES IN PACE: OBSERVER/RECORDER: M. Rehfeldt PACE SPEED(S): --------- 40MPH 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 X X 44 X X X 43 X X X X X 42 X X X X X 41 X X X X X 40 X X X X X 39 X X X X 38 X X X X X 37 X X X 36 X X X X X 35 X X X X 34 X X X 33 X 32 31 30 29 28 27 26 25 24 23 22 21 1 1 100 2 1 1 1 99 2 1 3 3 98 6 3 2 4 7 7 95 10 5 3 6 9 9 88 12 6 5 10 10 10 79 10 5 5 10 10 10 69 10 5 5 10 11 11 59 12 6 5 10 11 11 48 12 6 4 8 8 8 37 8 4 5 10 7 7 29 4 2 3 6 5 5 22 4 2 5 10 8 8 17 6 3 4 8 5 5 9 2 1 3 6 3 3 4 1 2 1 1 1 Transportation Department Traffic Division 100 44 MPH --------'-'----- 86 % ----------- 36 TO 46 MPH ---- SOUTHBOUND DIRECTION OF TRAVEL MPH 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 X 48 X 47 X X X 46 X X X X X 45 X X X X X X 44 X X X X X 43 X X X X X 42 X X X X X X 41 X X X X X X 40 X X X X 39 X X 38 X X 37 X X X 36 X 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 DATE: 08/26/10 TIME: 9:25 AM TO WEATHER: Clear & Warm CITY OF CARLSBAD SPEED SURVEY 10:00 AM TOTAL VEHICLES: CRITICAL SPEED: LOCATION: Avenida Encinas~O.6 mi s/o Palomar Airport Road VEHICLES IN PACE: OBSERVER/RECORDER: M. Rehfeldt ---------PACE SPEED(S}: 40MPH POSTED SPEED LIMIT SOUTHBOUND DIRECTION OF TRAVEL MPH # % I:# % %tile % # 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 X 49 X 48 X X X X 47 X X 46 X X X X 45 X X X X X 44 X X 43 X X X X X X 42 X X X X X X X 41 X X X X X X 40 X X X X X 39 X X 38 X X X 37 X 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 4 8 5 5 97 2 1 2 4 7 7 92 10 5 4 8 5 5 85 2 1 5 10 9 9 80 8 4 2 4 6 6 71 8 4 6 12 10 10 65 8 4 7 14 10 10 55 6 3 6 12 11 11 45 10 5 5 10 10 10 34 10 5 2 4 7 7 24 10 5 3 6 9 9 17 12 6 2 4 4 4 8 4 2 2 2 4 4 2 2 2 2 4 2 Transportation Department Traffic Division 100 46 MPH 84 % ----------- 38 TO 48 MPH NORTHBOUND DIRECTION OF TRAVEL MPH 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 X 49 X 48 X X X X X 47 X 46 X X X X 45 X X X X 44 X X X X 43 X X X 42 X X X X X 41 X X X X X 40 X X X X X 39 X X X X X X 38 X X 37 X X 36 X X 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21