Doored While Biking in Cambridge, MA: Who Is Liable and What to Do

A parked car looks harmless until its door swings open into the bike lane. Dooring is one of the most common ways cyclists get hurt on dense, car-lined streets like much of Cambridge, and it is also one of the clearer liability situations in Massachusetts bike law. Here is how the law treats a dooring crash and what to do if it happens to you.

What Dooring Actually Is

Dooring happens when a driver or passenger opens a car door into the path of a passing cyclist. The danger is concentrated in the strip of roughly two to four feet next to parked cars, often called the door zone. A rider moving at a normal pace has almost no time to react when a door opens a few feet ahead. The injuries are serious. A cyclist thrown into the door, or swerved into moving traffic to avoid it, can suffer broken bones, facial and dental injuries, concussions, and worse. Boston’s own cyclist safety reporting has repeatedly found dooring to be one of the single most common bicycle crash types in the area, accounting for more than one in ten reported bike collisions in the years studied.

Massachusetts Law Puts the Duty on the Person Opening the Door

Massachusetts is unusually clear on this point. Under Massachusetts General Laws Chapter 90, Section 14, no one may open a car door unless it is reasonably safe to do so without interfering with other traffic, and the statute names bicyclists and pedestrians specifically. Massachusetts sits in the minority of states that spell out that protection rather than leaving a cyclist to argue after the fact that they counted as traffic. A violation carries a fine of up to 100 dollars. The fine itself is small, but the citation matters far more in a civil claim, where it can serve as evidence that the person who opened the door was negligent. In plain terms, the law expects the person inside the car to look before opening the door, not the cyclist to anticipate a door that is not there yet.

Doored while biking in Cambridge? Get a free case review from a Cambridge bicycle accident attorney. Call 617-683-1983.

Fault Is Usually Clear, but the Insurer May Still Push Back

Because the legal duty sits with the person opening the door, dooring claims tend to be more straightforward than many other bike crashes. That does not mean the driver’s insurer will simply pay. A common tactic is to argue that you share the blame for riding too close to the parked cars or for not stopping in time. Massachusetts uses a modified comparative negligence rule under General Laws Chapter 231, Section 85. You can still recover as long as you are not more than 50 percent at fault, but your compensation is reduced by whatever share of blame is assigned to you, and at 51 percent you recover nothing. So an adjuster who can pin even 20 or 30 percent of the fault on you shrinks the payout accordingly. That is exactly why the citation, the photographs, and an early legal review matter so much. For a fuller walkthrough of how fault gets sorted out, see our guide on who is at fault when a car hits a cyclist.

Cambridge Bike Lanes and the Lingering Door Zone

Cambridge has spent years rebuilding its streets around the Cycling Safety Ordinance, first passed in 2019 and amended in 2020, which commits the city to installing roughly 25 miles of separated bike lanes. By late 2025 the city reported around 17 miles completed or under construction, with the current deadline set for November 2026. Many of these are parking-protected lanes, where the row of parked cars sits between moving traffic and the bike lane. That design cuts down on classic driver-side dooring, because the driver door no longer opens directly into the lane. It does not erase the risk. On a parking-protected street the passenger side now faces the cyclist, and passengers are far less likely than drivers to check for a bike before stepping out. On the many Cambridge streets that still carry an old-style painted lane running through the door zone, the original hazard remains. Knowing which kind of lane you were in can matter to how a crash gets analyzed later. Our overview of Cambridge’s most dangerous spots for cyclists covers where these conflicts tend to cluster.

What to Do If You Are Doored in Cambridge

Handle a dooring crash the way you would any car-versus-bike collision, with one wrinkle worth remembering.

• Call 911 and ask for a police response so a Cambridge Police Department crash report is created. That report is the official record of who opened the door.
• Get the name and information of both the driver and whoever opened the door, since they are not always the same person.
• Photograph the open door, the car’s position, the bike lane markings, and your bike and helmet before anything is moved.
• See a doctor promptly even if you feel able to ride away, because dooring injuries often involve the head and face and do not always hurt right away.
• Do not give a recorded statement to the other side’s insurer before you have spoken with a lawyer.

For a full day-by-day checklist, read our guide on what to do in the first week after a bike accident.

Talk to a Cambridge Bike Accident Lawyer

If a car door put you on the pavement in Cambridge, you should not have to fight the driver’s insurance company alone, especially when the statute is on your side. A Cambridge bicycle accident lawyer can secure the police report, deal with the adjuster, and make sure any early offer reflects the full picture of your injuries. We offer a free, no-pressure consultation to review what happened and explain your options. Call Melanson Law Group at 617-683-1983.