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Separated bike lanes near 929 Mass Ave

Mid-Mass Ave Safety Improvement Project

Project Complete: Installed Fall 2021

This page is no longer regularly updated. 

Through this quick-build project, we installed .92 miles of separated bike lanes on Massachusetts Avenue between Trowbridge Street (near Harvard Square) and Inman Street (near Central Square). Separated bike lanes create space that is physically separated from vehicle traffic, which improves safety and comfort for people biking. Our quick-build toolbox includes pavement markings, signs, and flex posts.

Project Area

A map showing the streets around the project area. The Project Area, Mass Ave between Trowbridge St and Inman St is highlighted. 


  • Improve safety for people biking in the project area
  • Improve safety for people walking at existing crosswalks
  • Improve safety for transit riders with enhanced markings and signage at bus stops
  • Identify opportunities to accommodate the loading needs of businesses
  • Implement changes in line with our Vision Zero Action Plan and meet the requirements of the Cambridge Cycling Safety Ordinance 

Previous Updates and Background

September 2021 - Installation Complete

The Mid-Mass Ave Safety Improvement Project was installed in September 2021. Changes included:

  • .92 miles of separated bike lanes on Massachusetts Avenue between Trowbridge St and Inman St;
  • pavement marking and signage updates for transit riders;
  • signage updates to improve pedestrian safety; and
  • a number of changes to parking and loading regulations to accommodate the needs of business owners and residents.

Read more here

August 26, 2021 - Installation Begins

On August 26, 2021, we shared the following implementation update.

During the week of August 30, we will begin preliminary implementation work, including updating signs and meters on side streets. The following week, we will install the separated bike lanes on Massachusetts Ave between Trowbridge St and Inman St. This work is weather-dependent and will take several days/nights to complete.

Please be mindful during this implementation phase as signs, markings, and parking regulations will be changing. Temporary parking restrictions will be in place as we work to install the project. These temporary restrictions are noted with red and white paper signs. We will also be updating the metal signs to indicate the new parking regulations.

July 9, 2021 - Implementation Update

On July 9, 2021, we shared the following implementation update.

Thank you to everyone who participated in the community process for this project. Due to ongoing shortages in construction materials, the flex posts will not be delivered until late-Summer. As a result, we will be delaying implementation until early August. If you have questions email us at tpt@cambridgema.gov.

May 26 - June 14, 2021 - Community Feedback Period

Between May 26 and June 24, 2021 community members were invited to share feedback on the plans by submitting comments through a feedback form or email. You can:

May 26, 2021 - Community Meeting

On Wednesday, May 26, 2021, we held a community meeting via Zoom to provide an update on the plans. You can view a PDF of the presentation; or watch, listen to, or read a recording of the meeting. The video recording is captioned in English.

March 15 - March 28, 2021 - Community Feedback Period

Between March 15 and March 28, 2021 community members were invited to weigh in on key decisions related to the design and share other general feedback. We collected feedback through/by:

A map of the existing parking inventory was also provided.

March 15, 2021 - Posters Placed in Project Area

On March 15, 2021 we posted flyers in the project area. The posters had key questions that will inform the design of the project. Mass Ave is wider at some points than at others. As a result, the primary questions are about where parking should be maintained. The signs gave location specific information, a short description of the project, and invited community members to share information about other things that they want us to consider as we develop the design.

  1. Blue posters were used in locations where we have to remove all of the parking. Photo location: Mass Ave at Ellery St
  2. Orange posters were used in locations where we have to remove one side of parking. Photo location: Mass Ave at Clinton St
  3. Yellow posters were used on side streets in locations where we can add meters to existing parking spaces. Photo location: Hancock St at Mass Ave
  4. Green posters were used in locations where we pre-determined that the parking has to be on the south side of the street to accommodate the Senior Center. Photo location: Mass Ave across from Inman St
  5. The green posters also contained information about the option to move the bus stop in front of City Hall to create new parking spaces. Photo location: Mass Ave at Inman St
  6. Pink signs were used on side streets in locations were we aren't making any changes. These signs were simply to alert people about the project. Photo location: Bigelow St at Dottie Doyle Way

A photo collage of the six types of posters that were put out in the project area.

Separated Bike Lane Example

Mt Auburn St at Holyoke St - Before and After

The images below show Mt Auburn St at Holyoke St before and after separated bike lanes were installed as a part of the Inner Mount Auburn Safety Improvement Project.

The left image shows Inner Mt Auburn St with a standard bike lane, travel lane, and a parking lane. The right image shows Inner Mt Auburn St with a bike lane, buffer area with flex posts, a travel lane, a parking lane, and daylighting.

Key Components of Separated Bike Lanes

  • Bike lanes create dedicated space for people who are biking.
  • Buffers (painted lines on the street) create space between people biking and people driving. They help prevent unintentional collisions that could cause serious harm to the people involved. Depending on the location, there may be a parking lane next to the buffer area. In these instances, drivers can use the buffer area to safely get in and out of the car and to load and unload items.
  • Flex posts are placed in the buffer area and serve as a vertical barrier in the buffer area.
  • Travel lanes allow space for people to drive down the street, but can be used by anyone.
  • Green markings help alert people turning from the travel lane that they should look out for people on bikes. These are generally installed at intersections and across driveways.
  • Parking creates space for people to store their vehicles while they are in the area. This part of the street may also be designated as loading zones, which help make it easier for delivery people to do their jobs.
  • Daylighting is when the parking lane is pulled back 20 feet to make it easier for people driving down the street and people waiting to cross the street to see each other. These areas are generally marked with lines on the ground. There may also be flex posts.

Why Install Separated Bike Lanes

Separated bike lanes provide more space and vertical separation between people on bikes and people in cars. More people are comfortable biking in separated bike lanes than in traditional bike lanes or in traffic with cars, buses, and trucks. Separated bike lanes also increase safety for people walking by reducing crossing distances. As we install separated bike lanes, we also look for opportunities to increase visibility at intersections, refresh crosswalk markings, and install appropriate pedestrian crossing signs.

Page was posted on 2/17/2021 5:17 PM
Page was last modified on 7/24/2023 10:21 PM
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