City officials announced on Tuesday their plans to replace existing bike lanes with protected bike lanes — known as cycle tracks — from the Boston University Bridge to Packard’s Corner. The lanes will be about two-thirds of a mile and use parked cars as a barrier between cyclists and vehicle traffic, a move meant to cut down on accidents that have become common along the heavily used road.

The city of Boston will install protected bike lanes on a stretch of Commonwealth Avenue, a victory for biking advocates who have pushed for the city to make it safer to cycle down the bustling thoroughfare.


The decision to install the protected bike lanes represents a turnaround for the administration of Mayor Martin J. Walsh, and could pave the way for more protected bike lanes in the city.

The city has long planned to repave the road, put in new curbs, and refurbish sidewalks on a portion of Commonwealth Avenue, but the administration had not planned substantial changes to its bike lanes. City officials in August were wary of adding a cycle track, saying major revisions could jeopardize the timeline of the construction project.

But after advocates continued pushing for more protections for cyclists, James Gillooly, the deputy commissioner of the Boston Transportation Department, said city officials knew they had to install cycle tracks.

“We took those concerns to heart, and the mayor took great interest in this project,” he said. “We went back to the drawing board to see what was the very best that we could do.”

Construction is scheduled to begin in the spring of 2016 as part of a $17 million plan. The city will have another community meeting on the design in early fall before bidding begins on the project.

The project, slated to be completed by fall 2017, will mean significant changes for cyclists, pedestrians, and drivers. In the middle of the street, officials will widen the swath of land for the Green Line, to improve safety for MBTA workers.


On the outbound side of the street, officials will remove one of the three lanes. On both sides of the street, two lanes will remain — one that is 10 feet wide, and another that is 11 feet wide.

The announcement of the new cycle track comes more than two years after 23-year-old Boston University graduate student Christopher Weigl was fatally struck by a tractor-trailer that was turning right onto St. Paul Street. Data from 2010 through 2012 showed that 68 bike crashes occurred along the area of the proposed cycle track.

Gina Fiandaca, who was named transportation commissioner in January, also touted the city’s plan to include “protected intersections,” which are rare in the United States, on the street.

Under the plan, officials will place physical barriers between bikes and vehicles at intersections, which will force drivers to slow down before turning. The change would help prevent the sort of “right-hook” collisions that killed Weigl.

Cycling advocates said the plans bring a new level of safety to one of the most heavily traversed streets for bikes in the city.

“I hope it saves lives, I hope it dramatically increases the safety for all of its users, and I hope it gives the public the confidence that we can do this here in Boston,” said Nicole Freedman, the city’s top biking official, who recently announced she will be leaving to work for the city of Seattle.


Freedman also said she hopes the cycle track will spur more conversations about bike safety in a city that was long known as dangerous for cyclists.

The new lanes would become the city’s most prominent cycle tracks. Boston has installed a cycle track on Mount Vernon Street in Dorchester, and officials will begin construction in the spring on 4 miles of protected bike lanes in the heart of downtown.

The move for more bicycle-safe streets marks a rapid change in the transportation culture of Boston in the past decade. In 2007, the same year Freedman helped launch Boston Bikes under Mayor Thomas M. Menino, the city had less than a mile of bike lanes.

Boston has 92 miles of bike lanes, though the city still lags behind other major American cities like Portland, Ore.

Gillooly said city officials had at least 30 meetings on the street in the past six months to help revise the plan to include safer streets for cyclists. He said he was glad the many meetings have paid off.

“Every step of the way, we were looking out for everybody’s interest,” he said. “It’s about reaching that right balance.”

Nicole Dungca can be reached at nicole.dungca@globe.com. Follow her on Twitter @ndungca.