“When you have to pull out into 40 mile-per-hour traffic from traveling at 15 miles per hour, you can get hit,” he said. “You risk your life.”

Alexander Frieden, who commutes from Somerville to the Longwood Medical Center area each morning, said these obstacles pose a potentially deadly hazard. When a car obstructs a cyclist’s path, he said, the person is forced to merge into the busy roadway, where motorists are traveling at much higher speeds.

It’s a problem that many Boston-area cyclists face almost every day: As commuters are pedaling along, a vehicle illegally parked in a designated bike lane suddenly confronts them.


To draw attention to the issue, Frieden rolled out a collaborative online tool this week where cyclists can submit photographs of cars and trucks parked in bikes lanes, and pinpoint the locations of the vehicles on an interactive map. The purpose of the project is to both draw attention to problem areas for bike commuters, and inform city planners in Cambridge, Boston, Somerville, and Brookline about spots where bicycle infrastructure could be greatly improved.

“Very quickly, you can see where there are issues,” said Frieden, a bioinformatics group leader at Brigham and Women’s Hospital. “I wanted, personally, something that people could see, and say, ‘Here are the dangerous parts where we need protected infrastructure.’”

The website, carsinbikelanesboston.com, is an offshoot of a project first launched by Nathan Rosenquist, a cyclist from New York City. Frieden said Rosenquist left the source code for his project open, on Github, making it easy to adapt and get a version for the Greater Boston area up-and-running smoothly.

“I went through a month-long process … trying to debug what wasn’t working and what was working,” he said, adding that he worked with Rosenquist remotely. “We got it working and launched it and have had a number of submissions.”


Since Monday, at least six people have added input to the project, he said. Users can go on the website, hit “submit,” and then add an image, the vehicle’s plate number, its precise location, and the date and time the driver was parked in the bike lane.

So far, three of the photographs featured on the website show large delivery trucks pulled to the side of the road, blocking a lane. Frieden said this is common — especially in the morning — as truck drivers struggle to find a place to pull over when unloading deliveries.

Frieden stressed that while he hopes people use the site, it’s important that they continue to report issues about vehicles parked in bike lanes to Boston’s 311 constituent services platform.

In Boston, drivers are not allowed to stop or park in a bike lane, and can get a parking ticket for doing so, according to the city’s website. Cambridge also doles out violations for obstructing the lanes.

The project comes as cities in the region add bike infrastructure to roadways. In Boston, city officials recently touted improvements such as painting new bike lanes, and building physically separated tracks for cyclists. Somerville has been adding “sharrows” — a shared-lane marking — and repainting bike lanes along busy thoroughfares. And in Cambridge, officials have taken steps to protect those most vulnerable on the streets.

While some have said the project is a way to “shame” drivers, Frieden sees it as a method of working more collaboratively with city planners and drivers.


“It’s not to shame drivers, it’s meant to get accurate information,” he said. “Although some people might use it for shaming drivers, my intent is to make sure this is an opportunity to learn what we could do better.”

Steve Annear can be reached at steve.annear@globe.com. Follow him on Twitter @steveannear.