Bus Priority

Cities can make buses travel better by redesigning streets to have dedicated lanes and redesigning signals to give more time to buses. The City's policies and plans direct city staff and departments to make changes that prioritize travel by public transit. These policies and plans include:

Below, you will find information on how City staff and departments have decided.

How do we decide where to put bus lanes and priority at signals?

In 2014, 2018 and 2022, the City studied bus delay and unreliability on most bus routes in Cambridge. In the 2018 study, City staff identified locations of concern where bus delay and unreliability are high. The 2022 study identified whether locations of concern still existed after the MBTA Better Bus Project made changes to bus routes. Click here to see the map of the locations of concern.

In locations of concern, the City's departments will consider installing dedicated bus lanes and priority at signals for buses. To do this, this may mean considering:

  • restricting parking and loading to specific hours of the day or all day
  • dedicating a travel lane to buses only
  • relocating bus stops to allow for buses to move more quickly through signalized intersections
  • giving more time at a signal for the directions that buses travel, especially when buses are delayed

City staff are researching additional ways to give priority on city streets to buses.

Where are there dedicated bus lanes in Cambridge?

For each street redesign project, the City thoroughly considers dedicated bus lanes and signal priority in creating the design of the street. You can learn more about upcoming and completed street redesign projects where dedicated bus lanes are/were considered.

Upcoming street redesigns where bus lanes are being considered

During the following street redesign projects, city staff will consider dedicated bus lanes and signal priority. Click links to see the project webpage

During the following street redesign projects, we considered dedicated bus lanes and will be installing new or upgraded bus lanes.

Completed street redesigns with bus lanes

We considered and built dedicated bus lanes in the following projects.

State government agencies built dedicated bus lanes in the following projects.

Frequent questions about bus lanes

What is a bus lane?

A bus lane is a part of the street that the City has dedicated to buses. To make this clear, we have added things to the street to make it as clear that the lane is dedicated to buses. You will see solid white lines to mark the edges of the bus lane, red lane markings in the bus lane, "Bus Only" text markings, and black and white traffic signs that say "Right Lane Bus Only". Some bus lanes may also allow bicycles; we have installed lane markings and signs that indicate that. At certain locations, motorists can enter a bus lane for a short distance. See the question below for more information on how we mark those locations.

Why create a bus lane?

Bus lanes make bus routes more reliable and make bus trips faster, especially during times when streets are congested. In Cambridge, this means improvements for riders who use MBTA Routes 1, 62/76, 64, 67, 70, 71, 73, 75, 77, employer and campus shuttles, MASCO M2 buses, and EZRide buses. We create bus lanes because the City's transportation and citywide mobility plans say this is important.

What vehicles can use a bus lane?

Bus lanes in Cambridge are for MBTA buses, shuttle operators, school buses, and emergency vehicles. Some dedicated bus lanes are also shared bus-bike lanes with cyclists sharing the bus lane with bus and shuttle operators.

When can a motorist enter a bus lane?

Motorists can enter a bus lane to access a parking lane or driveway and to turn right at the next intersection.

Where motorists need to access a driveway or parking lane to the right of a bus lane, motorists should enter the bus lane no farther than 50 feet from the driveway or open parking spot. Motorists must yield to buses and cyclists in the dedicated bus lane when making this movement. Motorists entering a driveway should double check for cyclists in the bike lane, too. We do not modify the bus lane markings or signage for these locations.

Where motorists need to make a right turn to enter a side street, we have designated a place for motorists to enter the bus lane about 100 feet from the intersection. We show that location by breaking the solid white lines and red markings and using a right-turn arrow marking. Motorists must yield to buses and cyclists in the dedicated bus lane and can only turn into the side street at those intersections. Motorists making a right turn should not enter a bus lane until they are at a broken or dashed white line.

Motorists can enter a bus lane to access the general travel lanes from a driveway or side street. Motorists should not drive in the lane.

Can a motorist park, load, or stop in a bus lane?

In most cases, a motorist cannot park, load, or stop in a bus lane.

On Massachusetts Avenue between Alewife Brook Parkway and Dudley Street, there are times of day when you may park or load in the bus lane on the southbound/Porter Square direction side of the street. Street signs will show the hours when parking and loading is allowed.

Where do traffic signals give priority to buses?

Concord Avenue - Design and planning ongoing

In 2020, the City won a grant to develop and install transit signal priority at city-owned traffic signals on Concord Avenue. In 2022 and 2023, the City and the MBTA worked on the design and planning for the installation of transit signal priority equipment. We expect to install this equipment and make changes to signal timing in 2023 or 2024. 

Massachusetts Avenue - Implemented 2017

In 2017, the City and the MBTA installed transit signal priority equipment at two locations on Massachusetts Avenue. This equipment allows traffic signals to give a few more seconds of green time to buses so that they can make a green light.

How well are the bus lanes and priority at signals working?

City analysis of bus lanes on Mass Ave Dudley to Alewife Brook Parkway

In 2023, the City reviewed the effect of bus lanes on Mass Avenue between Dudley Street and Alewife Brook Parkway. "The analysis shows that average travel time for Route 77 buses between Dudley Street and Alewife Brook Parkway significantly decreased after bus lanes were added. Bus travel times also became more consistent and predictable throughout the day."

Read the news item: Bus trips on north Mass Ave faster, more consistent with bus lanes

Read the memo: Post-implementation travel time analysis of Massachusetts Avenue

Pioneer Institute's Bus Rapid Transit Report

In 2022, the Pioneer Institute released a comprehensive report on the costs and benefits of bus rapid transit in Greater Boston. This report provides an overview of their study which concluded that bus rapid transit can offer cost-effective benefits as shown through the success of pilot programs. 

Read the report: Bus Rapid Transit - Costs and Benefits of a Transit Alternative

MAPC's "Get it Rolling" Guidebook

In 2021, the Metropolitan Area Planning Council released the "Get it Rolling" guidebook. This is a framework aimed to help transportation stakeholders improve their bus systems and infrastructure, launch pilot programs, and ensure community engagement. 

Read the guidebook: Get it Rolling - A Brief Guide to Mobilize Bus Improvements in Greater Boston

Transportation Research Board-Transit Cooperative Research Program

In 2019, the Transportation Research Board's Transit Cooperative Research Progam published Report #207: Fast-Tracked: A Tactical Transit Study. This study is a snapshot of the quick-build strategies that cities have used to improve travel for people on buses and streetcars. This report included both bus priority projects in Cambridge. To read this report, visit the report's webpage.


The Barr Foundation funded part of the City's Mount Auburn Bus Priority pilot project. The Barr Foundation and partners at StreetFilms reported on the successes of various projects in the Boston area. Click below to watch the StreetFilm

More information

For more information about the City of Cambridge transit program, click here.

For more information about bus priority in Cambridge, please contact Andrew Reker at areker@cambridgema.gov or 617/349-6959.