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HomeMy WebLinkAbout2016-08-01; Traffic Safety Commission; ; Modify limits of existing 40 mile per hour speed zone on a portion of Black Rail Roadr- CITY OF CARLSBAD TRAFFIC SAFETY COMMISSION STAFF REPORT COMMISSION MEETING OF: August 1, 2016 ITEM NO. 6A LOCATION: Black Rail Road from Poinsettia Lane to Sapphire Drive Alex Amirnovin INITIATED BY: 5976 Black Rail Road Carlsbad, CA 92011 REQUESTED ACTION: Modify limits of existing 40 mile per hour speed zone on a portion of Black Rail Road. BACKGROUND: DATA: The Engineering and Traffic Survey currently on file for Black Rail Road justifies a 40 mile per hour speed zone from Sapphire Drive to Aviara Parkway (see Exhibit 1). Based on the presence of single family homes on a portion of Black Rail Road, staff is recommending a modification to the limits of this speed zone so that Black Rail Road between Sapphire Drive and Poinsettia Lane can be appropriately posted as a 25 mile per hour speed zone. The portion of Black Rail Road between Sapphire Drive and Poinsettia Lane is approximately 1,100 feet in length and 40' wide curb to curb. Sapphire Drive is a private gated street at the northern terminus of Black Rail Road which provides access to the large Marbrisa community. There are six single family homes with frontage upon Black Rail Road, which differentiates it from the other portions of Black Rail Road (see Exhibit 2). The California Vehicle Code defines a "residence district" as, "a portion of a highway and the property contiguous thereto, other than a business district, (a) upon one side of which 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" Based on this definition, the required ratio to meet the residence district requirement is 13 houses per every quarter of a mile or approximately 1 house per 100 feet. Per Section 22352 of the California Vehicle Code, a residence district street may be posted with a prima facie 25 mile per hour speed limit without justification of an Engineering and Traffic Survey. The linear distance which encompasses the six homes on Black Rail Road is 560 feet. This spacing meets the definition of residence district and therefore, can be appropriately signed as a 25 mile per hour speed zone. Page 1 RECOMMENDATION: The Traffic Safety Coordinating Committee recommends modifying the limits of the existing 40 mile per hour prima facie speed limit upon Black Rail Road so that the portion of said roadway between Sapphire Drive and Poinsettia Lane can be appropriately posted as a 25 mile per hour speed zone. NECESSARY CITY COUNCIL ACTION: An ordinance will be required to be adopted by the City Council to modify the limits of the existing 40 mile per hour prima facie speed limit upon Black Rail Road Page 2 C CITY OF CARLSBAD 0 ENGINEERING AND TRAFFIC SURVEY STREET: Black Rail Road LIMITS: Sapphire Drive to Aviara Parkway FACTORS A. Prevailing Speed Data: Direction: Northbound/Southbound . Date of Speed Survey 3/17/15 Location of Speed Survey 0.1 Mile s/o Corte Orchidia 85th Percentile 40MPH 10 MPH Pace 32to42 MPH Percent in Pace 75% B. Accident History: (8/01/13 through 7/31/15) Speed-Related Accidents 2 Pedestrian and/or Bicycle Accidents 0 Total Accidents 2 C. Traffic Factors: Average Daily Traffic 1,200 -North of Aviara Parkway (2008); 1,400 -South of Martingale Court (2008) Traffic Controls Traffic Signals at Aviara Parkway and Poinsettia Lane Pedestrian/Bicycle Traffic Low Bicycle Lanes No Striped Bicycle Lanes On-Street ParkinA Parking Allowed on Both Sides D. Roadway Factors: Circulation Element Street Classification Unclassified Length of Segment 0.85 Miles Roadway Width Varies Between 36 Feet and 48 Feet Number of Lanes One Lane Each Direction Vertical Alignment Roadway Grades Vary from 1.00% to 8.19% Horizontal Alignment Relatively Straight Sidewalks Sidewalk on Both Sides Except 325 feet of East Side Driveways 12 Driveways Street LiohtinA Limited Street Lighting E. Special Conditions: Travel lanes are separated by a 55-foot long raised median north of the intersection at Aviara Parkway and the remainder of the road has a double-vellow centertine. F. Adlacent Land Uses: Two Water Reservoirs, SinQle-Family Residential, Church, Open Space G. Remarks/Conditions Not Readilv Annarent: Vertical curves on Black Rail Road limit stoooinA sioht distance. 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, effective November 7, 2014, 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 oostina of 40 MPH is found to be annrooriate and iustified. I. Approvals: efRecertification of existing speed zone per Sections 22357, 22358 and 40) 02 of the California Vehicle Code. □ Establishment of new speed zone. ~Af L II J;;.olr:3 Approved i, r Ll1 @,." Doug Bilse U • Date City Traffic Engineer CATR2279 NOTE. Appropriate speed survey Is attached hereto and made a part hereof. . C DATE: 3/17/15 TIME: 10:10AM. TO WEATHER: Sunny & Mild CITY OF CARLSBAD SPEED SURVEY 0 12:05 P.M. TOTAL VEHICLES: CRITICAL SPEED: LOCATION: Black Rail Road-0.1 mi. s/o Corte Orchidia VEHICLES IN PACE: OBSERVER/RECORDER: J. Gale ---------PACE SPEED(S): SOUTHBOUND DIRECTION OF TRAVEL MPH # % 'Z# % %tile % # 65 64 63 62 61 60 59 58 57 56 55 64 53 52 51 50 49 48 47 46 45 A X 44 X 43 X 42 41 X 40 X X 39 X X X 38 37 X X X 36 X 35 X X X X X X 34 X X X X X X 33 A 32 X X X X X X X 31 X X 30 X X 29 X 28 X 27 X X 28 25 24 23 22 21 1 1 100 2 1 99 2 4 4 4 99 4 2 1 2 1 1 95 1 2 3 3 94 4 2 3 3 91 6 3 1 2 3 3 88 4 2 2 4 3 3 85 2 1 4 8 6 6 82 4 2 1 2 7 7 76 12 6 4 8 7 7 69 6 3 3 6 9 9 62 12 6 7 14 13 13 53 12 6 7 14 9 9 40 4 2 2 4 6 6 31 8 4 7 14 11 11 25 8 4 2 4 4 4 14 4 2 2 4 2 2 10 1 2 3 3 8 4 2 1 2 1 1 5 2 4 3 3 4 2 1 1 1 1 2 1 Public Works Department Traffic and Mobility Division 100 --~----=4~0 ____ MPH 75 % _____ _:..;: ____ _ 31 TO 41 __ _::..:..__ MPH NORTHBOUND DIRECTION OF TRAVEL MPH 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 X 47 46 y X 45 44 y -\( 43 X y y 42 y X 41 -y 40 X 39 X \( X X X 3B X X 37 X X X X X 36 X y X y X 35 X 34 X X X 33 X X X 32 X 31 30 y X 29 2B X 27 y 26 25 24 23 22 21 C 0 LOCATION MAP NOT TO SCALE Black Rail Speed Zone EXHIBIT 2