The Manager's report back on that the Traffic, Parking, and Transportation Department and Department of Public Works meet with and receive input from residents living on the streets in the impacted area to discuss strategies to mitigate and reduce overflow and cut through traffic, including the proposal mentioned in the order, or other traffic calming or traffic diversion methods, and report back to the Council on any short-term recommendations no later than December 19

Subject: AR-22-79 – November 14, 2022

This memorandum has been prepared in response to Awaiting Report Item AR-22-79 from the November 14, 2022 City Council Meeting requesting that the Traffic, Parking, and Transportation Department and Department of Public Works meet with and receive input from residents living on the streets in the impacted area to discuss strategies to mitigate and reduce overflow and cut through traffic, including the proposal mentioned in the order, or other traffic calming or traffic diversion methods, and report back to the Council on any short-term recommendations no later than December 19, 2022. The order further requests that a final report be submitted no later than March 27, 2023. This memo is intended to respond to the request for short-term recommendations. In October 2022, the City of Cambridge made changes to Garden Street to add a quick- build separated bike lane as part of the Garden Street Safety Improvement Project. Major changes to the street included changing the operation of Garden Street to eastbound one-way for vehicles between Huron Avenue and Concord Avenue and a reduction in parking spaces. Work included new traffic signals, updated metal street signs, road markings, bicycle stencils, flex posts, and colored surface treatments. This project is part of the implementation of the Cycling Safety Ordinance. The Cycling Safety Ordinance, passed in 2019 and amended in 2020, represents a shift from designing our streets primarily around car transportation to also prioritizing cycling, which is resulting in changes in how we allocate space on City streets. The Cycling Safety Ordinance mandates the accelerated development of a full network of separated bike lanes across the City. The creation of this alternative transportation network is a significant step forward towards creating a sustainable, healthy future for Cambridge, but it does not come without other impacts. In a dense city with limited space on our roadways, making space for separated bike lanes is not easy, and results in reductions in parking and changes to how the roadway network operates. We recognize that it is challenging for many residents, that our roads are becoming more complex, and that we are making difficult trade-off’s. The decision to include the one-way conversion of Garden Street came from the input of the members of the community who took part in the public process in advance of the Page 2 of 9

Brooke McKenna, Acting Chief

project implementation. The conversion to one-way was appealing both to local residents who prioritized retaining parking as well as local cyclists who preferred one- way bike lanes on each side of the street, as safety is better provided for with a consistent bike lane alignment along the longer corridor. Removal of one of the two travel lanes provided enough space to both retain parking in areas most-requested by the community and to add the one-way bike lanes on each side. We recognize that community engagement could have been improved across the broader community that is now affected by the conversion to one-way and we hear the many voices that feel like they were not involved in planning conversations. This is an area we are committed to continuing to improve. Data We collected data in and around the project area on October 12 (before we installed changes to Garden Street), and again during the first week of December. These counts help us to monitor the impacts of the project and we plan to continue interim data collection and analysis in the coming months and share this publicly. Final data collection that reflects the longer-lasting impacts of the project will follow in early Spring 2023. Traffic impacts from the project were most significant in the days immediately following implementation. Our observations have shown that some of the additional traffic has abated and that the immediate impact on side streets has started to come down as traffic patterns have adjusted (See Appendix A). While there is still some increased traffic on certain side streets, the total volume is within the range across side streets from October before implementation. When significant changes are made to traffic patterns, it can take three to six months for drivers to adjust to new routes. We are currently six weeks post implementation, and we are still seeing road users learning and making adjustments. This is mostly from people outside of the neighborhood who came to the area infrequently or that are newly returning to the area after COVID-19 office re-openings. People unfamiliar with the area tend to make peculiar choices in response to road changes, and we are still in the settle- in period, without a full picture of what the fully developed effects will be. We recognize that this is also challenging for residents and we will continue to hear from the community, make adjustments, and collect data and observations. Methods The City uses an independent traffic data collection firm to collect speed and volume data. Equipment is placed on the street in the same locations each time to allow for comparisons over time. Weather can impact our ability to collect data, as the equipment can malfunction due to snow, but we will make all efforts to take advantage of good weather days between now and March/April to demonstrate trends over time. In the most recent data collection, and moving forward, we will be collecting two days of data each month. We then average the two days to compare to the single day of data collection done prior to the project implementation. Page 3 of 9

Brooke McKenna, Acting Chief

With speed data, we track the 85th percentile speed which is consistent with industry best practice. This is the speed at or below which 85 percent of the drivers travel on a road segment. Most motorists (typically 75 percent according to research) drive within 5mph of the 85th percentile speed, making it more representative of the speeds experienced on the roadway when compared to average speeds.

Summary Graphs showing the comparison between the pre- and post- project speeds and volumes are included in Appendix A, and we’ve summarized some key points here: Overall speed impacts are relatively small and include both increases and decreases. For example, the 85th percentile speed on Shepard Street decreased from 22 mph to 20 mph. On Newell Street, the 85th percentile speed increased from 14 mph to 16 mph.

In a number of locations, the 85th percentile speed is slightly above the speed limit, similar to where the numbers were prior to the project implementation. For example, Linnaean Street saw an increase from 27 mph to 28 mph, Bond Street saw an increase from 22 mph to 23 mph, and Concord Avenue saw an increase from 29 mph to 30 mph. Several streets saw small reductions in speed, including Raymond Street moving from 24 mph to 23 mph and Shepard Street dropping from 22 mph to 20 mph.