Mt. Auburn Street at Aberdeen Avenue Intersection Safety Improvement Project

Installation of Flex-Posts and Curb Work Complete

We've completed the installation of flex-posts, precast curbs and the bicycle jughandle at Homer Ave. This completes the installation of the bicycle improvements on Mt Auburn St.

Modifications to Signal Timing at Homer Ave

City staff continue to monitor traffic and safety conditions in the project area. We are planning adjustments to signal timing at Mt Auburn St and Homer Ave. These adjustments will:

• Provide additional time in the light cycle for Mt Auburn St traffic.
• Remove pedestrian recall during the evening. In the evening, pedestrians will need to push the button to receive a green light. The pedestrian signal will continue to come up automatically during the morning when pedestrian volumes are highest. 

Installation of Flex-Posts and Precast Curbs

Beginning next week, we will install flex-posts and precast curbs. Flex-post installation will occur first, followed by precast curbs at a later date. This work will take place during the day and will require temporary closure of the bike lane.

This work is tentatively scheduled for Tuesday, May 13th, with additional installation dates to follow as needed.

Installation of Red and Green Pavement Markings

New lane lines and traffic pattern changes are in effect.

We still need to install green bike lane markings and red bus lane markings. Some of this work will require temporary lane and driveway closures. Work will occur overnight, beginning at 8 p.m. to minimize impacts.

Making Adjustments

With the recent changes, we are continuously monitoring traffic patterns and making adjustments, as needed.

We recently adjusted signal timing at Homer Ave to allow more vehicles to progress through the intersection. Additional improvements are planned for the coming weeks. These improvements are being made on an ongoing basis.

What to Expect:

• Temporary closure of the bike lane to install flex-posts and precast curbs.
• Overnight pavement marking work with occasional lane and driveway closures.
• Daytime installation of signage and signal modifications, as needed.

Pavement Marking Installation Begins Tuesday, April 23

Work will occur overnight, beginning at 8 p.m., and will last approximately two to three nights. Most major line markings will be completed during this time, including turn-only lanes and bike lane markings.

Additional work will take place at later dates for crews to install red and green bus and bicycle markings. Some of this work will take place during daytime hours.

No parking impacts or traffic detours are expected, but temporary lane closures may occur. Slow down for work crews and keep an eye out for posted signage when installation is underway.

What to expect:

• New traffic pattern for all travel modes.
• Installation of additional signage and signal work to complement new road markings.
• Crews working in the area during both the daytime and overnight hours. Exercise caution when driving through work zones.

Traffic Signal Work Complete

During the Months of February and March, the City's traffic signal contractor, Dagle Electrical Construction, installed new traffic signal equipment on Mt Auburn St. This included:

• Overhead signals at Aberdeen Ave and Mt Auburn St. The new signal includes a dedicated left turn signal onto Aberdeen Ave, improving clarity and driver compliance with existing turning regulations.
• Additional signals, including bike signals, that are needed for the separated bike lane. These signals are installed but not yet in operation.

Separated Bike Lane Installation Coming Soon

This Spring, we will install pavement markings and flex-posts for the project. Pavement markings will be installed as shown in the design plans below. This includes installing the new bike lane and turn-only lanes that are planned for the project. We expect installation to begin soon. This work is weather dependent. We will send another update once work is scheduled.

Pavement marking line work will occur during the overnight hours, beginning at 8 p.m. and last approximately 2-3 nights. After the initial lane markings are installed, additional work will take place during the daytime hours, including red bus lane markings and sidewalk repair work.

No parking impacts or traffic detours are expected, but temporary lane closures may occur. Slow down for work crews and keep an eye out for posted signage while implementation is occurring.

Traffic Signal Installation Update

On Tuesday, November 21, the City's traffic signal contractor, Dagle Electrical Construction, installed the foundation for the new signal at intersection of Aberdeen Avenue and Mt. Auburn Street.

Next Steps: The foundation will require two to three weeks for the concrete to settle. Once the concrete foundation settles, we will install the new signal arm. We expect this to occur this December. At that time, we will switch traffic operations over to the new signal. We will send out another update before this work occurs.

Sidewalk Impacts

Underground utility conflicts required us to place the foundation of the signal in the path of the existing sidewalk. Crews are now installing a temporary asphalt sidewalk around the foundation. We expect work on the temporary sidewalk to finish today (Wednesday, November 22). Unforeseen circumstances may require some work to finish the week of November 27.

Next spring (2024), the City will replace the temporary asphalt sidewalk with a permanent concrete sidewalk at this location. Over the winter, the City will coordinate with the owners of above-ground utilities to create room for a wider sidewalk. The new sidewalk will span the width between the traffic signal foundation and the curb.

Project Expected to Finish Spring 2024

We expect that once the new signal is operational, it will be too cold to complete the remainder of the project this winter. New pavement markings to extend the separated bike lane and make other changes to the layout of the street will occur in the spring of 2024.

Beginning the week of Monday, November 6, the City's traffic signal contractor, Dagle Electrical Construction, will begin installing the foundation of a signal mast arm at the intersection of Aberdeen Avenue and Mt. Auburn Street.

• Where: The work will take place on the south side of Mt. Auburn Street opposite Aberdeen Avenue.
• When: Work will take place one to two days next week between 7 a.m. and 3 p.m.
• What will happen: The contractor will excavate the ground and pour new concrete. Crews will work on Mt. Auburn Street and there will be daytime lane closures. No interruption to signal operations is anticipated at this time. 
• Next steps: Once built, the foundation will require two to three weeks for the concrete to cure. Once the concrete foundation cures, we will install the new signal mast arm. We expect this to occur in late November/early December. At that time, we will switch traffic over to the new signal.

Project Expected to Finish Spring 2024

At this time, we expect that once the new signal is operational, it will be too cold to complete the remainder of the project this fall. New pavement markings to extend the two-way separated bike lane and make other changes to the layout of the street will most likely occur in the spring of 2024.

On September 12, from 5 p.m. to 7 p.m., we hosted a drop-in project open house which took place outside the Star Market at 699 Mt Auburn St.

At the Open House we:

• Discuss updated plans for the design of the project
• Provide information regarding next steps, including the schedule for project implementation
• Informally discuss the project with attendees

Click here to view materials shared at the open house.

Click here for more information.

On Wednesday, August 23, 2023 from 6 p.m. to 8 p.m., we held a virtual community meeting over Zoom.

Meeting Materials

• Meeting slides
• Meeting video recording
• Meeting transcript

City staff gave a presentation regarding project background, relevant city policies and ordinances, and shared the revised plans since the Project Open House in May. Attendees had an opportunity to provide feedback and ask questions.

Next Steps

• Second Project Open House on Tuesday, September 12th
• Project implementation will begin later this Fall.

Meeting Update

Please review the slides, recording, or transcript for a full overview of what was discussed during the meeting.

Revised Design Key Features

• Two-way separated bike lane on the north side of the street. This revised the previous design of a one-way bike lane on either side of the street.
• No left turn from Mt Auburn St directly into the shopping center. Left turns will access the shopping center by turning left onto Homer Ave and using the Homer Ave entrance.
• Changes to signal timing to improve crossing Mt Auburn St on foot. This includes providing more time to cross the street and reducing the wait time for a green walk signal.

On Wednesday, May 24, from 4:30 p.m. to 6 p.m. at the Collins Branch of the Cambridge Public Library (64 Aberdeen Ave), we held an open house to discuss the Mt. Auburn Street at Aberdeen Avenue Intersection Safety Improvement Project.

During the open house, we:

• Shared plans for changes to Mt Auburn Street, between Belmont Street and Brattle Street
• Provided background on the city goals and policies, such as Vision Zero, the Cambridge Bike Plan, and other nearby city projects
• Discussed the project with residents and abutters and take feedback 

Click here to view materials shared at the open house.

This was not the only opportunity to hear about the project from City staff: we will be holding a more in-depth online community meeting later this year. Sign up for the project email list to stay informed.

Email Project Manager Andreas Wolfe at awolfe@cambridgema.gov if you have a question or comment that you would like to receive a response to. 

The Brattle Street Safety Improvement Project installed separated bike lanes and pedestrian crossing islands on Brattle Street. These safety improvements were made between spring and summer 2023. 

The separated bike lanes on Brattle Street end at the intersection of Brattle Street, Mt. Auburn Street, and Aberdeen Avenue. The Mt. Auburn Street at Aberdeen Avenue Intersection Safety Improvement Project will connect to the Brattle Street project. 

Brattle Street Safety Improvement Project Plans 

Click to enlarge this image. 

As part of the Five-Year Street and Sidewalk Reconstruction Plan, Huron Avenue is being reconstructed between Fresh Pond Place and Fresh Pond Parkway. Improvements include adding three new fully-accessible crosswalks, making improvements to existing crossings, adding a two-way separated bike lane along the Fresh Pond Reservation, and planting trees. 

A future project will add quick-build separated bike lanes to Aberdeen Avenue, connecting the Huron Avenue bike lanes to Mt. Auburn Street. The City is coordinating with utility companies to determine the best time to start this project, which will have no impacts on existing parking. 

Click here to read more about the Huron Avenue and Cushing Plaza Improvements Project. 

Engineering Plans

• Final engineering plans (October 2023)

Roll Plans

• Old project roll plan (May 2023)
• Updated project roll plan (August 2023)

Meeting Materials

• May 2023 Open House boards
• August 23, 2023 Virtual Meeting slides
• August 23, 2023 Virtual Meeting Video recording 
• August 23, 2023 Virtual Meeting transcript
• September 12, 2023 Open House boards

This project covers Mt. Auburn Street between Belmont Street and Brattle Street.

Click here for to view a larger project map.

In 2019, the Cambridge City Council passed the Cycling Safety Ordinance. The 2019 Ordinance requires the City to install separated bike lanes when:

• Roads are being reconstructed as part of the City’s Five-Year Plan for Streets and Sidewalks
• AND those roads are designated for greater separation in Cambridge’s 2020 Bicycle Network Vision

In 2020, the Cambridge City Council passed amendments to the ordinance, requiring the installation of about 25 miles of separated bike lanes within the next five to seven years. The ordinance requires that the City install separated bike lanes on:

• All of Massachusetts Avenue
• Garden Street, eastbound from Huron Avenue to Berkeley Street and westbound from Mason Street to Huron Avenue
• Broadway from Quincy Street to Hampshire Street
• Cambridge Street from Oak Street to Second Street
• Hampshire Street from Amory Street to Broadway
• 11.6 miles in other locations from the 2020 Bicycle Plan

Looking for information on other streets and transportation projects in the City? Three City departments collaborate on the design, community engagement, installation, and construction for street and transportation improvements: the Community Development Department, Public Works Department, and Traffic, Parking, and Transportation Department.

• Current street and transportation projects
• Cycling Safety Ordinance-related projects
• City's Five Year Plan for Streets and Sidewalk Reconstruction 
• Map of Cambridge's existing and currently-planned bike facilities, updated in December 2022. This map is for planning purposes and is subject to change - it is not a route map.