A communication transmitted from Louis A. DePasquale, City Manager, relative to Awaiting Report Item Number 18-55, regarding a report on improving road safety conditions on Clinton Street

City of Cambridge Community Development Department Iram Farooq, Assistant City Manager Department of Public Works Owen O’Riordan, Commissioner Traffic, Parking, and Transportation Joseph E. Barr, Director MEMORANDUM To: Louis A. DePasquale, City Manager From: Joseph E. Barr, Director of Traffic, Parking, and Transportation Iram Farooq, Assistant City Manager for Community Development Owen O’Riordan, Commissioner of Public Works Date: July 11, 2018 Re: Awaiting Report 18-55: Report on Improving Road Safety Conditions on Clinton Street This memo is in response to Order #3 from the May 14, 2018 City Council Meeting (Awaiting Report 18-55) regarding a request for improved road safety conditions on Clinton Street following receipt of a resident petition by the City Council. According to the petition, residents have reported instances of speeding on their street, including a recent crash involving a vehicle backing out of a driveway. Speed data collected during the peak hour (4:30pm- 5:30pm) on a weekday evening showed that the 85th percentile speed, which is the speed below 85 percent of the vehicles travel and the standard for measuring vehicle speed in traffic analysis, was 22 mph. The speed limit on the street is 25 mph. The results also showed 33 vehicles travelled on Clinton Street during that hour, with none of the vehicles traveling at speed above 25 mph. The highest speed recorded on the street during the count was from one vehicle traveling at 24 mph. A graph summarizing the results of the speed and volume study is shown in Figure 1. Figure 1: Speed Distribution on Clinton Street 0 1 2 3 4 5 6 7 8 9 14 15 16 17 18 19 20 21 22 23 24 Number of Vehicles Speed (MPH)

Page 2 of 2 As the results of the speed and volume study indicate that road users are travelling at less than the speed limit, we do not recommend any short-term changes to the roadway infrastructure at this time. In general, traffic calming changes to streets are constructed in conjunction with other roadwork such as paving and sidewalk reconstruction. At this time no roadway work is scheduled for Clinton Street. We will continue to monitor traffic speed and evaluate the potential for traffic calming measures if Clinton Street (or the streets at either end of Clinton Street) is scheduled for roadwork in the future.