The Manager's report back on Garden Street Safety Improvement Project local traffic analysis

The order further requests that a final report be submitted no later than March 27, 2023. This memorandum is intended to respond to the request for the final report.

Executive Summary

In October 2022, the City of Cambridge installed quick-build separated bike lanes on a portion of Garden Street as part of the implementation of the City’s Cycling Safety Ordinance. To accommodate separated bike lanes on each side of the street and retain some parking where it was requested by community members, the City changed the operation of Garden Street between Huron Avenue and Concord Avenue from a two- way road to an eastbound one-way for vehicles.

This report, prepared by the City of Cambridge Traffic, Parking, and Transportation

Department responds to Awaiting Report Item AR-22-79, which requests a final report on how resident concerns about Garden Street switching to one-way traffic are being addressed.

This report:

Evaluates the effects of the Garden Street Safety Improvement Project on traffic

speeds, traffic volumes, and parking on Garden Street and the surrounding Examines the potential outcomes of returning the section of Garden Street from Linnaean Street to Huron Avenue to two-way vehicular traffic.

Garden Street Safety Improvement Project Local Traffic Analysis — Executive Summary

Page 2 of 54 Responds to comments from residents about parking on Garden Street, trucks on Walker Street, and traffic at the Garden/Huron intersection. Makes recommendations on further measures the City could take to address resident concerns. Key takeaways include: Speeds: Count data shows that speeds have increased slightly on all streets that were monitored. Since no changes were made to the geometry or character of the streets surrounding the project, we believe a combination of data collection margin of error and placement of the devices account for much of the changes in vehicular speeds. Traffic volume: Traffic volume data shows that, while many streets in the neighborhood have increases in vehicle volume, these increases are not out of scale with traffic volumes on similar streets throughout the City. Parking availability: Parking counts indicate ample parking availability along Garden Street and neighboring streets at midday and overnight. While some streets have high parking utilization, street parking across the study area is underutilized according to parking management standards. Changing traffic patterns on Garden Street: Restoring the section of Garden Street from Linnaean Street to Huron Avenue to a two-way for vehicles would likely reduce comfort and safety for people biking and walking, and increase queues, gridlock, and congestion near the Garden/Huron/Sherman intersection. While this change may divert some cut-through traffic from Raymond Street, traffic patterns will likely not change to the extent that residents hope for. However, there are measures the City could take to slow or divert traffic on side streets, which are outlined in this report. Trucks on Walker Street: It is unlikely that the state will approve a truck restriction on Walker Street based on MassDOT’s criteria. However, based on the parking utilization on the street, there may be an opportunity to remove spaces at the bend to keep trucks from getting stuck while turning. Moving parking on Garden Street: We do not plan to move parking on Garden Street: the current design has safety benefits, moving parking to the north side would not add many parking spaces, and we have heard primarily positive feedback from the users of the existing spaces. Our recommendation is that we leave the design of Garden Street itself as-is and continue to work on solutions for traffic and speed management within the greater project area. This report provides detail on a number of alternatives to achieve the desired results without major modifications to the project. The following ideas are explored in the report and could help reduce cut-through traffic in the neighborhood, but represent fairly significant changes to the operation of the streets. The City would need to consult the residents of the area before implementing any of these measures. Recommendations and potential changes include: No left turn sign on Walker Street at Linnaean Street for peak hours: Reduction in cut-through traffic on Raymond Street that originates from Massachusetts Avenue (Shepard Street to Walker Street to Linnaean Street to

Garden Street Safety Improvement Project Local Traffic Analysis — Executive Summary

Page 3 of 54 Raymond Street). Reduction in cut-through traffic along Walker Street and Graham and Parks School. Parking chicanes on Raymond Street: Potential for speed reduction.

All-way stop at Raymond Street and Huron Avenue intersection: Further

analysis and observations are required, but this could potentially improve safety at this location for all users if this type of control is warranted.

Fernald Drive and Robinson Street one-way pair: Reduced cut-through traffic

on Madison Street, Robinson Street, and Raymond Street as well as an opportunity to add more permit parking on a street with high parking utilization. The remainder of this report examines the data, suggestions from the community, and potential traffic and speed management solutions in more detail. Use the table of contents below to navigate to specific sections: Contents Executive Summary ....................................................................................................

1 Project Background .................................................................................................... 4 Feedback Since Installation .................................................................................... 5 December 15 Council Order Response ...................................................................... 6 Changes Since December Council Order Response ..............................................

6 Speed and Volume Data ............................................................................................ 7 Key Takeaways ....................................................................................................... 7 Data Collection ........................................................................................................ 7 Methods and Notes .................................................................................................

8 Summary ................................................................................................................. 9 Streets with Increases in Volume .......................................................................... 14 Comparisons to Pre-COVID Volumes ................................................................... 21 Comparisons to Citywide Volumes .......................................................................