CMA 2017 #297 · Agenda item attachment · Nov 13 2017

CITY OF CAMBRIDGE Traffic, Parking and Transportation 344 Broadway Cambridge, Massachusetts 02139 www.cambridgema.gov/traffic Joseph E. Barr, Director Phone: [phone removed] Brooke McKenna, Assistant Director Fax: [phone removed] MEMORANDUM To: Louie A. DePasquale, City Manager From: Joseph E. Barr, Director of Traffic, Parking, and Transportation Date: November 6, 2017 Re: Awaiting Report 17-101: Report on the feasibility of reducing the speed limit on Magazine Street, as well as other traffic calming measures This memo is in response to Order #4 from the October 2, 2017 City Council Meeting (Awaiting Report 17-101) requesting that City staff determine the feasibility of reducing the speed limit and installing traffic calming measures to reduce the incidents of speeding. In order to assess existing conditions along the corridor, we completed a 48-hour automatic recorder (ATR) count on Magazine Street south of Cottage Street. The ATR counted hourly traffic volumes, traffic speeds, and classification of vehicle for the entire period. The data indicates that Magazine Street carries a daily traffic volume of approximately 4,200 vehicles per day, including 1,650 vehicles per day in the northbound direction and 2,550 vehicles per day in the southbound direction. The data indicate that the 50th percentile speed of vehicles is 21 miles per hour while the 85th percentile speed is 26 miles per hour. In analyzing speed, the operating speed of a street is typically considered to be the 85th percentile, meaning that 85 percent of drivers are traveling at that speed or slower. This data indicates that the majority of drivers traveling on Magazine Street are traveling at no more than one mile per hour over the 25 mph speed limit, and that a little less than half are traveling at or below 20 miles per hour. The chart below shows the distribution of speeds on Magazine Street.

Page 2 of 2 Magazine Street is subject to the Prima Facie (unposted) speed limit of 25 miles per hour, which was recently lowered from 30 miles per hour consistent with all other streets Citywide. Under state law, the Traffic, Parking, and Transportation Department does have the authority to designate Safety Zones with a speed limit of 20 miles per hour. Our current policy is to promote the 20 miles per hour Safety Zones in squares, smaller business districts, and other locations where pedestrian and bicycle activity is highest. Given the context and land use along Magazine Street, combined with the lack of existing speeding issues (as shown by the recently collected data), we would not recommend making any changes to the speed limit at this time. Similarly, given that there is not a significant problem with vehicles traveling over the speed limit on Magazine Street, we do not believe that this is a high priority location for the installation of traffic calming measures. We will continue to monitor conditions on Magazine Street and take appropriate actions in the future if required.