Centre Street Design Project

View the Technical Memorandum

• We will not be removing any traffic signals on Centre Street. The existing signals that are missing from the diagrams in the May 31 presentation will be corrected when an updated design is posted on the website, by the end of July.

• A tech memo to support the design is posted online. We collected speeds and traffic volumes in two locations on Centre Street for 3 days, and turning movement counts at 9 signalized intersections for a 12 hour period on one day in January 2023. Similar analysis was conducted in 2019.

• There are three major safety advantages of going from four lanes to three:

1. It creates room for a left turn lane. a) People who want to turn left can get into their own lane and not feel pressure from drivers behind them who want to go straight. It also eliminates weaving around someone waiting to make a left turn. b) A driver in the left turn lane only needs to wait for a gap in one opposing lane of traffic versus two. c) At signalized intersections, we can have separate left turn phases for drivers making a left from Centre Street onto a side street. 
2. It reduces the double threat problem for pedestrians, where one driver stops for a pedestrian, and a driver in the second lane proceeds without seeing the pedestrian because their view is blocked by the first driver.
3. It reduces the opportunity for speeding. With only one travel lane, drivers can only go as fast as the person in front of them. Driving at a slower speed improves safety because: a) It reduces the driver's stopping distance and widens their cone of vision. b) It reduces the force of a collision and decreases the likelihood of severe or fatal injury, especially for crashes involving older adults.

• Centre Street already has a large number of signalized intersections. While signals allow for the safe movement of pedestrians and vehicles, they also introduce delay for people walking and driving. Adding traffic signals at all unsignalized crosswalks would increase driver travel time more than the proposed changes by adding to the stop-start experience of driving on the corridor. Additionally, the currently unsignalized intersections are unlikely to meet federal MUTCD guidelines for the addition of traffic signals. The planned design is intended to improve safety while minimizing the amount of additional delay for people driving.

• Reducing the number of travel lanes from four to three is important to do because it will reduce the opportunity for excessive speeding at all times of day and all days of the week, even without additional traffic enforcement. The design change also addresses crosswalk visibility issues. The Boston Police Department has at times conducted enhanced enforcement on Centre Street. When the City measured speeds in 2023, they had returned to pre-enforcement levels. The Boston Police Department has indicated that their staffing levels do not allow them to provide continuous enforcement.
• Automated enforcement with traffic cameras is not currently legal in Massachusetts and therefore is not an option on Centre Street.

• Flashing lights which pedestrians activate with a push button, also known as Rapid Flash Beacons, can be used as a supplemental safety device at a crosswalk without traditional traffic signals. While they can help reduce crashes, they do not fully address the visibility issues where a vehicle stopped in one lane obscures the view of a pedestrian to a driver traveling in the adjacent lane. They also do not reduce speeding or address left turn crash risk. Use of multiple beacons in close proximity diminishes their value as drivers tend to tune out a large number of flashing lights.

• Bus lanes are most appropriate in locations with a high frequency of buses and a large number of riders. Centre St. has neither relative to other places in Boston with bus lanes. In addition, bus lanes would prevent the addition of left turn lanes, which are essential to the flow of vehicles on the street. Without left turn lanes, cars traveling through would be forced to wait behind left-turning cars adding more delay.

• A small number of parking spaces will be removed to enhance visibility of pedestrians and cyclists at the intersections. In the draft design, 95% of the parking spaces would be retained. We will update this figure if it changes during the final design.

• Double parking usually happens when people need to park for a short period of time, and they can’t find a space or don’t want to be blocked in. We will create more short-term parking spaces to support the need for loading, pickup, takeout and delivery, and other short-term activities.

• We based our draft parking proposal on a study completed in 2019 by MAPC that showed parts of the corridor where there were many free spaces and people parking for longer than two hours. We reduced the number of four hour spaces in a revised plan that we will post on the website by the end of July.

• Boston Transportation Department has been hiring additional parking enforcement staff to increase parking enforcement throughout the city, including in West Roxbury.

• We will collect speed data and traffic counts in January of 2024 in the same locations where we collected them in January of 2023 to see if speeding has been reduced. Reductions in crashes will take a longer time to assess.

• The design for Centre Street is intended to accommodate current traffic volumes with minimum additional delay to avoid increasing cut through traffic on side streets. To verify any impacts, we will do traffic counts along selected side streets before and after the project is in place and will evaluate the results over the winter. We will report back our findings in the spring along with a mitigation plan if a substantial increase is observed on any of the side streets.

• The city’s Safety Surge program prioritizes speed humps on residential streets using risk-based criteria, including crash history and demographics most likely to be injured in a crash. While most residential streets in Boston will eventually get speed humps, the streets immediately adjacent to Centre Street will come in future years.  However, if we observe a substantial increase in traffic on side streets after the Centre Street project is implemented, we will accelerate speed hump installation as part of a mitigation plan. .

• The traffic signal at Belgrade and the West Roxbury Parkway is owned by DCR. We are reaching out to see if adjustments could be made to the timing of that signal to help process more vehicles during the afternoon peak hours.

• Changing street direction can have unintended consequences on neighboring streets that could make it difficult for people to access their homes. We reserve this tool for very limited situations and use it on a case-by-case basis.

• We have chosen to start with the core Centre Street business district, subject to additional evaluation, we are open to extending the project area to include more of Centre Street and Spring Street in future years.

• No two streets are ever exactly the same, but there are several other area streets that provide a useful comparison. Like Centre St, both examples are thriving neighborhood business districts with a similar volume of weekday vehicular traffic served by a single lane in each direction with turn lanes.

1. In Cambridge’s Central Square, Massachusetts Avenue between Main Street and Albany Street provides a single travel lane in each direction, turn lanes at some intersections, a southbound bus lane, parking, and protected bike lanes. The street is a similar width to Centre St and  serves through traffic while supporting a mix of local businesses. 
2. In Brookline, Harvard Street through Coolidge Corner has a single travel lane in both directions with turn lanes at some intersections. It has parking on both sides and unprotected bike lanes between the parked cars and the travel lanes. The street serves a high-frequency bus route (#66) and a large number of pedestrians.

The Centre Street project is designed around the specific geometry, traffic patterns, and local business needs of the street. However, the examples above show how similar lane configurations can function well, provide safety for all road users, and support local businesses.