Eyes On the Street: Filling In Gaps In Cambridge’s Bike Network

7:47 AM EDT on September 8, 2025

A man in a grey shirt bikes down a bike lane between a sidewalk and a row of parked cars on a street lined with 4-5 story buildings and trees. — After a one-year delay imposed by City Councilors, the City of Cambridge has installed a new parking-protected bike lane on Main Street between Central and Kendall Squares.

This fall, bike commuters in Cambridge are riding upgraded bike routes across the city as the city draws closer towards its 2027 deadline for building out a citywide network of protected bike lanes.

Under the Cycling Safety Ordinance of 2020, the Cambridge city government is required to build 22.6 lane-miles of protected bike lanes across the city by the end of 2026.

This year, the City of Cambridge plans to complete 3.6 miles' worth of new bikeways on its way towards meeting that requirement next year.

We took a bike ride around the city last week to check out some of those projects underway:

Main Street, One Year and 37 Crashes Later

One of the projects wrapping up this month is on a 0.3-mile segment of Main Street, from Lafayette Square in the west to Portland Street in the east, plus a very short segment near Albany Street that extends the bikeway to Technology Square.

Two people on bikes ride down a protected bike lane on a city street lined with 4-5 story older industrial buildings and trees. — New separated bike lanes on Main Street in Cambridge, pictured here looking east near the intersection with Bishop Allen Drive. The high-rises of Kendall Square are visible in the distance.

In Lafayette Square, the project connects to existing protected bike lanes on Massachusetts Avenue. It also connects to recently-upgraded bike lanes on the rest of Main Street, where the city installed two short segments of protected bike lanes east of Portland Street last year.

Main Street still has a short segment of unprotected paint-only bike lanes east of Technology Square, in the vicinity of intersecting bikeways on Vassar and Ames Street.

The Main Street project has some notable history. Last year, a slim majority of Cambridge City Councilors (Mayor E. Denise Simmons and Councillors Paul F. Toner, Joan Pickett, Ayesha M. Wilson, and Patricia M. Nolan) voted to delay this bikeway, among several others across the city, and postpone the Cycling Safety Ordinance's overall deadline until the end of 2026.

Up until that vote, the city had planned to install these safety improvements on Main Street between Mass. Ave. and Portland Street last summer.

In the year since that vote, the City of Cambridge's records indicate that drivers have caused at least 37 crashes on the entire length of Main Street.

In 5 of those crashes, a driver ran into a person riding a bike, and 4 other crashes, the driver drove into a pedestrian.

The Vassar Street bike lane reaches the river

The new Main Street bike lanes will connect to one of Cambridge's oldest on-street protected bike lanes, the sidewalk-level bikeways on Vassar Street through the MIT campus.

Until this fall, those protected bike lanes ended abruptly near Amesbury Street and Amherst Alley, leaving a quarter-mile gap between the Vassar Street bikeways and the Paul Dudley White bike path along the Charles Riverfront:

A sidewalk-level protected bike lane, which ends in the middle distance and merges into the street. — The end of the existing eastbound sidewalk-level protected on Vassar Street near Amesbury Street, pictured on Sept. 4, 2025.

But work is currently underway to delineate new protected bike lanes on that gap. Workers have already scrubbed older lane markings off the pavement, and the layout of the new lanes has been roughed out in spray paint:

Spray-painted white lines mark out future lane markings on a city street with patchy asphalt pavement. — New lane markings for planned protected bike lanes, which will run between the curb and a lane of on-street parking, have been roughed in on the western end of Vassar Street between Amesbury Street and Memorial Drive.

Project plans call for curbside bike lanes that would be protected from traffic with flexible-post bollards and segments of on-street parking on alternating sides of the street.

There's currently no crosswalk across Memorial Drive at the end of Vassar Street, so the city also plans to add new wayfinding signage to direct bike traffic coming to or from the riverfront path to use the signalized crossings at Amesbury Street, one block to the east, instead.

Westbound bike traffic will also be have the option of connecting to the newly improved bike connections to the B.U. Bridge by riding on a short segment of the Memorial Drive sidewalk west of Vassar Street.

River Street gets some pavement

A multi-year reconstruction of River Street is also expected to wrap up before the end of the season, although it's still under very heavy construction. When complete, there will be a new sidewalk-level bike lane running from Memorial Drive to a rebuilt Carl Barron Plaza in Central Square, providing an eastbound complement to the Western Avenue protected bike lane that Cambridge completed in 2016.

The project has been snarling traffic on River Street since 2022, but in a sign that it's really drawing closer to its conclusion, workers were out last week laying a fresh coat of asphalt on several blocks near Central Square:

Freshly laid asphalt on a street that's otherwise surfaced in dirt through the middle of a city neighborhood. — Workers are laying fresh pavement on segments of River Street this fall as the project nears the end of a multi-year reconstruction project.

The finished project will also create a dedicated bus lane along most of River Street to benefit the MBTA's route 70, which is slated to become a frequent-service bus route under the T's proposed bus network redesign.

A rendering of a street shown in cross-section with sidewalks, a general travel lane, a dedicated bus lane, and a raised cycle track. — Rendering of River Street's future layout, courtesy of the City of Cambridge.

In addition to new bike and bus lanes on River Street, the completed project will also add new traffic-calming infrastructure and sidewalk accessibility improvements on several intersecting streets.

And also: Mass. Ave., Broadway, and Cambridge Street

We didn't get photos on this particular excursion, but a number of other bikeway projects have been installed this summer or are in the works this fall:

The city installed a short segment of new protected bikeways on Waverly Street, which connects Cambridgeport to the northern side of the B.U. Bridge rotary.
On Massachusetts Avenue north of Harvard Square, workers have removed the central median as a necessary step towards installing new protected bike lanes. The project will also add a dedicated bus lane and new bus boarding platforms for the MBTA's route 77, and safety enhancements at crosswalks.
The city recently repaved Aberdeen Avenue, a short street near Fresh Pond that links protected bikeways on Huron Avenue and Mount Auburn Street. The finishing touches for the project will include new flexpost-protected bike lanes that will run along the street's wide tree-lined median.
There are also new protected bike lanes on Broadway between Portland Street (with a connection to the Hampshire Street bikeway) and Columbia Street. The Cycling Safety Ordinance requires the city to extend these bike lanes all the way to Quincy Street at the edge of Harvard Yard by the end of next year: