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HomeMy WebLinkAbout2008-04-07; Traffic Safety Commission; ; Update on Status of Proposed Changes to the Carlsbad Residential Traffic Management Program (CRTMP)( CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: April 7, 2008 ' LOCATION: Citywide INITIATED BY: Deputy City Engineer ITEMNO. 6A REQUESTED ACTION: Update on Status of Proposed Changes to the Carlsbad Residential Traffic Management Program (CRTMP). BACKGROUND: The Carlsbad Residential Traffic Management Program (CRTMP), which was approved by the City Council in May 2001, provides citizens a three phase approach to address traffic concerns in Carlsbad neighborhoods. The three phases developed by staff and City Council appointed citizens included: the first phase was designed to investigate the problems and involve the neighborhood; the second devoted to study the traffic problems, design of the measures needed to solve those problems and assignment of priority ranking; and the final phase bringing allocation of funds and final, permanent installation of the traffic calming measure. The final phase culminates with the monitoring of the finished program for effectiveness in solving the issue(s) that generated the whole process. - Since inception of the CRTMP, staff desires to update the document language, insert a minimum threshold point ranking system, and introduce two new elements in. the traffic calming toolbox. These elements include: (1) a reduced all-way stop control warrant; and (2) vertical deflection measures. These modifications would require the recommendation of the Traffic Safety Commission and ultimately City Council approval. The following outlines the new tool box elements: REDUCED ALL-WAY STOP CONTROL WARRANTS ON LOCAL STREETS: At the request of City Council, staff was asked to explore the possibility of including criteria in the CRTMP for all-way stop control. The existing publication does not address all-way stop control as a traffic calming measure. The evaluation of all-way stop control warrants on local streets would be separate from the warrants identified in the California Manual on Uniform Traffic Control Devices (MUTCD). Therefore, staff conducted nationwide research of other local governments adopting a reduced all-way stop control warrant for local streets. The following language for a reduced all-way stop control warrant is under review by staff: "The City of Carlsbad may consider the following guidelines when determining if an all-way stop is appropriate at any intersection of public local streets maintained by the City. Note, in the interest of overall public safety, the City may qualify or disqualify any proposed location based on any one, or none of the guidelines listed below. Typically, the following will be considered before an all-way stop is installed: 1. Sight Distance: The presence of any non-removable sight obstruction problem at the intersection may necessitate the need to install an all-way stop. 2. Residence District: a. The major street must have a curb-to-curb width ofno more than 40 feet. b. The major street must satisfy the requirements of a "residence district" as defined by the California Vehicle Code.· CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: April 7, 2008 3. Hourly Volume Requirements: ITEMNO. 6A a. The combined pedestrian, bicycle and motor vehicle volume entering the intersection from all approaches must average at least 300 units per hour for any eight hours of an a~erage day; and b. The combined pedestrian, bicycle and motor vehicle volume from the minor street (all approaches) must average at least 120 units per hour for the same eight hours. 4. Daily Volume Requirements: The vehicular average daily traffic volume from either approach of the major street should not exceed 5 times the vehicular average daily traffic volume from any one approach of the minor street. Five times was utilized as an upper limit to balanced traffic flow. Once five times was exceeded, imbalanced flow would exist. Therefore, the reduced all-way stop would not be applicable. S. Collision History: The intersection has experienced two or more reported collisions in a 24-month period of a type that is susceptible to correction by the proposed stop signs. 6. Petition: A positive petition of at least 67% of the property owners/residents along the existing major street (limits of which shall be determined by City staff) may be required, where appropriate. Those who sign the petition must agree to the placement of stop signs and advance warning signs as determined by City staff." • The aforementioned guidelines are intended for use on local streets within the City's defined residential district. All other stop sign requests would be evaluated using the criteria found in the California Manual on Uniform Traffic Control Devices. VERTICAL DEFLECTION MEASURES: Staff is evaluating vertical deflection measures with the Carlsbad Fire Department for acceptability. Vertical deflection measures include: speed cushions, speed lumps, and speed tables. Each measure is defined as follows: Speed cushions are manufactured rubber devices approximately 6 feet in width and 7 feet in length. The device has a vertical deflection of 3 inches. Exhibit 1 depicts a photograph of a speed cushion. The speed cushions are placed in a series across the width of the roadway to maximize effectiveness. A 3 to 4 foot gap is typically provided between each cushion to allow the wheelbase of emergency service vehicles to avoid the device. Exhibit 2 depicts a typical set- up for speed cushion placement. Speed lumps are defined the same as a speed cushion. However, a speed lump would be formed by city maintenance crews or a contractor. The dimensions of the speed lump are the same as for the speed cushion, but the exactness of the installed speed lump may vary because it is formed, not pre-fabricated. Speed tables can be pre-manufactured or asphalt constructed. This device spans the entire width of the roadway. Dimensions ofthis device include arise of3-¼ inches over 6 feet, a flat surface of 10 feet of no elevation change, and a fall of 3-¼ inches over 6 feet. Therefore, the entire length of the speed table is 22 feet. Exhibit 3 depicts a photograph of an asphalt formed speed table. CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: April 7, 2008 ITEMNO. 6A An information package regarding these vertical deflection measures was presented to the City's Fire Department. A review of the information package was conducted with Jim Weigand, Fire Marshal, on March 13, 2008. At the request of Mr. Weigand, a "test-deck" be constructed so that emergency response vehicles can travel both the speed cushion and speed table. An April 2008 evaluation is planned. RECOMMENDATION: Staff continues to evaluate a reduced all-way stop control warrant and the ve1tical deflection devices. At the request of the Fire Department, a "test deck" utilizing vertical deflection will need to be established before including a vertical deflection element in the new Residential Traffic Management Program publication. The revised publication of the Carlsbad Residential Traffic Management Program is being prepared for review and . approval at the Traffic Safety Commission meeting in May 2008. NECESSARY CITY COUNCIL ACTION: No action at this time. ( Exhibit 1 : Speed Cushion Exhibit 2: Example of Speed Cushions in a Series ( Exhibit 3: Example of Asphalt Speed Table