Is Lane Splitting Legal in Massachusetts?

No. Lane splitting is illegal in Massachusetts. The controlling statute is M.G.L. c. 89, sec. 4A, which says that operators of motorcycles “shall not ride abreast of more than one other motorcycle, shall ride single file when passing, and shall not pass any other motor vehicle within the same lane, except another motorcycle.” That last clause is the whole answer. A rider may pass another motorcycle inside a shared lane; a rider may not pass a car, a truck, a van, or a bus inside a lane that car, truck, van, or bus is occupying. The same section separately requires that every driver keep the vehicle “entirely within a single lane,” which independently rules out riding the painted line between two lanes of traffic. Massachusetts has never enacted an exception for slow traffic, for stopped traffic, or for filtering to the front at a red light, so the answer does not change because the cars were not moving. A violation is punishable by a forfeiture of up to one hundred dollars under M.G.L. c. 89, sec. 5, but the fine is rarely the expensive part. The expensive part is what an insurance company does with the citation after a crash. To talk through a motorcycle crash with a Massachusetts attorney, call Jim Glaser Law at (617) JIM-WINS; the first telephone consultation is free.

What Section 4A Actually Says

Section 4A is two sentences long and it does four separate jobs. Read in full:

“When any way has been divided into lanes, the driver of a vehicle shall so drive that the vehicle shall be entirely within a single lane, and he shall not move from the lane in which he is driving until he has first ascertained if such movement can be made with safety. The operators of motorcycles shall not ride abreast of more than one other motorcycle, shall ride single file when passing, and shall not pass any other motor vehicle within the same lane, except another motorcycle.”

The first sentence applies to everybody on the road, in a car or on a bike. It contains a positioning rule (stay entirely within one lane) and a lane-change rule (do not leave your lane until you have first determined the move can be made safely). Note the order of operations in that second clause. The statute does not ask whether the lane change turned out to be safe. It asks whether the driver ascertained that it could be made safely before starting the move. A rider who checks a mirror, sees nothing, and moves over has not necessarily satisfied it, because a mirror is not the whole picture on a motorcycle.

The second sentence adds three motorcycle-specific rules on top:

1. No more than two motorcycles abreast. A group can ride two across in a lane. Three across is a violation.
2. Single file when passing. Whatever the group is doing the rest of the time, the pass itself happens one at a time.
3. No passing another motor vehicle within the same lane, unless the vehicle being passed is another motorcycle.

Rule three is the lane-splitting prohibition, and it is worth noticing how it is written. The statute does not use the phrase “lane splitting.” It bans a maneuver, described functionally: passing a motor vehicle inside the lane that vehicle occupies. Whether the rider was moving at seventy miles an hour between two lanes of highway traffic or rolling at four miles an hour past a stopped delivery truck, the maneuver is the same one the statute names.

Three Maneuvers That People Confuse With Each Other

Most disagreements about this subject come from people using one word for four different things. Massachusetts law treats them differently, so the vocabulary matters.

Lane splitting means riding between two lanes of traffic moving in the same direction, usually along the painted line, to get past vehicles. This is illegal in Massachusetts twice over. It violates the same-lane passing ban in sentence two, and it violates the entirely-within-a-single-lane requirement in sentence one.

Lane filtering means moving to the front of stopped or nearly stopped traffic, typically at a red light, between the stopped cars. A handful of states have written filtering exceptions into their vehicle codes with conditions attached, such as a speed cap or a limit to roads with a certain number of lanes. Massachusetts has not. There is no filtering carve-out anywhere in chapter 89, and the same-lane passing ban contains no exception for stopped traffic. Riders sometimes assume that because the cars are not moving, no pass is occurring. The statute does not measure passing by the other vehicle’s speed.

Lane sharing means two motorcycles occupying a single lane side by side. This one is legal, within limits. Section 4A permits riding abreast of one other motorcycle, which is two motorcycles across, and prohibits three. When the pair is passing another vehicle, they have to go single file to do it.

Passing another motorcycle in the lane is also legal. The final clause of section 4A carves it out explicitly. A rider can pass another rider inside the same lane. The exception is narrow and it says “another motorcycle,” not “another small vehicle,” so it does not extend to mopeds, motorized bicycles, or anything else that falls outside the c. 90, sec. 1 definition of a motorcycle.

Answer Capsule

Lane splitting is illegal in Massachusetts. Under M.G.L. c. 89, sec. 4A, operators of motorcycles “shall not ride abreast of more than one other motorcycle, shall ride single file when passing, and shall not pass any other motor vehicle within the same lane, except another motorcycle,” and the same section requires every driver on a way divided into lanes to keep the vehicle “entirely within a single lane”. Lane filtering, meaning moving between stopped cars to the front at a light, is also illegal, because Massachusetts has enacted no filtering exception and the statute does not measure passing by the other vehicle’s speed. Two motorcycles riding side by side in one lane is legal; three abreast is not, and a passing maneuver must be made single file. A violation carries a forfeiture of not more than one hundred dollars under M.G.L. c. 89, sec. 5. In an injury claim, a splitting violation does not automatically bar recovery: M.G.L. c. 231, sec. 85 makes violation of a statute evidence of negligence rather than an automatic bar, reduces damages in proportion to the injured person’s share of fault, and cuts off recovery only if that share is greater than the total fault of the parties being sued. Call Jim Glaser Law at (617) JIM-WINS; the first telephone consultation is free.

The Penalty on the Ticket

Chapter 89 carries its own penalty section. M.G.L. c. 89, sec. 5 provides that whoever violates sections one to four C, with stated exceptions, “shall, upon complaint made within three months after the commission of the offense, forfeit not more than one hundred dollars”.

So the ceiling for the citation itself is one hundred dollars, and there is a three-month window for bringing the complaint. That is a small number, and it is the reason many riders conclude the rule is not worth taking seriously.

That conclusion misreads where the cost lives. A civil motor vehicle infraction sits in the driving record, and the record is what the insurer reads when it prices the policy at renewal. More importantly, the citation becomes a document in the claim file if the ride ends in a collision. An adjuster evaluating a claim does not weigh a one-hundred-dollar forfeiture. The adjuster weighs a piece of paper, generated by a police officer at the scene, that says the rider was doing something the statute prohibits. The distinction between a civil infraction like this one and an actual criminal charge is covered in more detail in is speeding a crime in Massachusetts.

Passing on the Right Is a Different Rule Entirely

Riders often ask a follow-up question that sounds like the same question and is not: can I pass on the right?

That is governed by M.G.L. c. 89, sec. 2, not section 4A. Section 2 sets the default that a driver passing a vehicle traveling in the same direction “shall drive a safe distance to the left of such other vehicle and shall not return to the right until safely clear of the overtaken vehicle”. It then lists the three situations where passing on the right is permitted: the driver may overtake and pass on the right, if the roadway is free from obstruction and wide enough for two or more lines of moving vehicles, when the vehicle being overtaken is “(a) making or about to make a left turn, (b) upon a one-way street, or (c) upon any roadway on which traffic is restricted to one direction of movement.”

Read section 2 and section 4A together and the practical rule emerges. On a multi-lane one-way roadway, a motorcycle may pass on the right, because section 2 permits it. What the rider may not do is make that pass inside the lane the other vehicle is occupying, because section 4A forbids it. The pass has to happen in a lane of its own. Slipping up the right edge of an occupied lane is not a legal pass on the right; it is same-lane passing with a different name.

Section 2 also contains a passing duty that reaches motorcyclists, though not by the route most riders assume. The sentence reads: “If it is not possible to overtake a vulnerable user, as defined in section 1 of chapter 90, or other vehicle at a safe distance in the same lane, the overtaking vehicle shall use all or part of an adjacent lane, crossing the centerline if necessary, when it is safe to do so and while adhering to the roadway speed limit”. A motorcycle is not a vulnerable user. The definition in M.G.L. c. 90, sec. 1 covers a pedestrian and a person operating a “bicycle, handcycle, tricycle, skateboard, roller skates, in-line skates, non-motorized scooter, wheelchair, electric personal assistive mobility device, horse, horse-drawn carriage, motorized bicycle, motorized scooter, or other micromobility device”, and a motorcycle appears nowhere in that list. The duty still reaches a rider, through the second limb of the sentence, “or other vehicle”. The distinction is worth getting right, because what the sentence requires is specific: the overtaking driver must move into the adjacent lane, crossing the centerline if that is what it takes, rather than squeeze past inside the lane. It is a useful provision to point at when a driver claims a rider appeared out of nowhere during the driver’s own squeeze past.

What a Splitting Violation Does to an Injury Claim

Here is the question underneath the question. A rider was splitting or filtering, a driver changed lanes into them, and the rider is now hurt. Is the claim dead?

No, not automatically. Massachusetts is a modified comparative negligence state and the governing statute is M.G.L. c. 231, sec. 85. Four features of that section matter here, and each one is written into the text:

A statutory violation is evidence, not a verdict. Section 85 says that “the violation of a criminal statute, ordinance or regulation by a plaintiff which contributed to said injury, death or damage, shall be considered as evidence of negligence of that plaintiff, but the violation of said statute, ordinance or regulation shall not as a matter of law and for that reason alone, serve to bar a plaintiff from recovery.” The citation goes into the evidence. It does not end the case by itself.

Two conditions sit in front of that clause and both are worth noticing, because insurers tend to skip them. The clause is written around violation of a “criminal statute, ordinance or regulation,” and a section 4A violation is charged as a civil forfeiture under section 5 rather than as a crime, so whether the clause reaches it at all is a question worth raising rather than conceding. The clause also requires that the violation “contributed to said injury, death or damage”. A violation that made no difference to how the collision happened, such as splitting a lane a quarter mile before a driver ran a red light at an intersection, establishes nothing under section 85. The same reading applies to the helmet rule, and it is worked through in detail in Massachusetts motorcycle accident law, which also explains why an injured rider has no personal injury protection coverage to fall back on.

Damages are reduced in proportion. Recovery is allowed but “any damages allowed shall be diminished in proportion to the amount of negligence attributable to the person for whose injury, damage or death recovery is made.” A rider found twenty percent responsible recovers eighty percent.

The bar is greater-than, and it is measured against all defendants combined. Contributory negligence does not bar recovery “if such negligence was not greater than the total amount of negligence attributable to the person or persons against whom recovery is sought”. The rider’s share is compared to the total of everyone being sued, not to any one defendant, and the combined total equals one hundred percent. Fifty percent is not a bar. Fifty-one is.

The burden is on the other side, and the rider starts with a presumption. The statute places the burden of alleging and proving the plaintiff’s negligence on “the person who seeks to establish such negligence,” and states that “the plaintiff shall be presumed to have been in the exercise of due care.” Section 85 also abolishes the assumption of risk defense outright, so an insurer cannot argue that a person who chose to ride a motorcycle accepted whatever happened next.

The practical translation is that a splitting violation is a fault-allocation problem, not an automatic loss. How Massachusetts assigns those percentages in practice is covered in how fault is determined in a Massachusetts car accident and in comparative negligence and partial fault.

Why the Insurer’s First Theory Is Almost Always “The Rider Was Splitting”

Insurers know section 85 as well as anyone. That is exactly why the splitting allegation shows up so often, including in crashes where nobody split anything.

The allegation is cheap to make and expensive to disprove. It usually arrives as a driver’s statement along the lines of “he came up between the cars” or “he came out of nowhere.” Nothing in that sentence has to be true for it to become the anchor of the adjuster’s fault analysis, and once it is in the file it tends to stay. If it sticks, the insurer moves the rider’s share of fault up, and every dollar of the claim comes down proportionally.

Two things push back on it, and both of them are gathered in the first days, not later:

The physical record. Where the motorcycle came to rest, where the debris field is, the location and direction of the scrape on the car, and whether the damage pattern is consistent with a vehicle changing lanes into a motorcycle already established in the lane. Photographs taken at the scene do work that memory cannot do six months later.

The independent account. A witness who was three cars back, a nearby business camera, a dash camera in a following vehicle. Camera footage is routinely overwritten in a matter of days or weeks, which is why the request has to go out early.

Riders should also expect a call from the other driver’s insurer asking for a recorded statement, often within a day or two and often framed as routine. What that call is for, and why it is not a neutral formality, is covered in giving a recorded statement to an insurance company and in dealing with the insurance adjuster after a Massachusetts crash.

Gear, Passengers, and the Rest of the Equipment Rules

Two other requirements come up constantly in the same conversation, and both live in M.G.L. c. 90, sec. 7.

Head protection is mandatory in Massachusetts, for the operator and for a passenger. Section 7 requires that “every person operating a motorcycle or riding as a passenger on a motorcycle or in a sidecar attached to a motorcycle shall wear protective head gear conforming with such minimum standards of construction and performance as the registrar may prescribe,” and it makes the operator responsible for not carrying an unhelmeted passenger. Eye protection is required as well when the motorcycle has no windshield or screen: the operator “shall wear eye glasses, goggles or a protective face shield”. Section 7 also provides that no operator may carry a passenger unless the motorcycle is designed to carry more than one person, and that a passenger may not ride in front of the operator.

The helmet requirement interacts with a claim the same way the splitting rule does, through section 85. It is evidence, weighed in proportion, not a switch that turns the case off.

The Deadline

Massachusetts gives three years. M.G.L. c. 260, sec. 2A provides that except as otherwise provided, “actions of tort, actions of contract to recover for personal injuries, and actions of replevin, shall be commenced only within three years next after the cause of action accrues.”

Three years sounds generous and is not, because the useful evidence in a disputed-fault motorcycle case has a much shorter life than the deadline does. Video is gone in weeks. Witnesses move. The vehicles are repaired or scrapped. Claims involving a public employer or a government entity carry their own separate and much shorter notice requirements, which is one of several reasons the date on the calendar is a poor guide to how long a rider actually has. The deadline landscape is laid out in the statute of limitations for personal injury in Massachusetts.

For riders in the state’s highest-volume crash corridors, county-level and town-level crash patterns are published in the Massachusetts crash report, built from MassDOT records. For the motorcycle-specific picture, including which municipalities record the most motorcycle crashes and why the majority of them happen mid-block on city streets rather than on highways, see where most motorcycle accidents happen in Massachusetts.

Frequently Asked Questions

Q: Is lane splitting legal anywhere in Massachusetts? A: No. M.G.L. c. 89, sec. 4A applies statewide to every way divided into lanes. There is no local ordinance, road type, or traffic condition that creates an exception, and the statute contains no carve-out for slow or stopped traffic.

Q: Is lane filtering at a red light legal in Massachusetts? A: No. Filtering to the front of stopped traffic between vehicles is the same maneuver the statute prohibits, and Massachusetts has enacted no filtering exception of the kind a few other states have adopted. The prohibition in section 4A is written around passing a motor vehicle within its lane, and it does not turn on how fast that vehicle is going.

Q: Can two motorcycles ride side by side in one lane in Massachusetts? A: Yes. Section 4A permits a rider to ride abreast of one other motorcycle, which means two across. Three abreast is a violation, and when the group passes another vehicle the riders must go single file.

Q: Can a motorcycle pass another motorcycle in the same lane? A: Yes. That is the one express exception in section 4A, which prohibits passing “any other motor vehicle within the same lane, except another motorcycle.” The exception is limited to motorcycles as defined in M.G.L. c. 90, sec. 1.

Q: What is the fine for lane splitting in Massachusetts? A: M.G.L. c. 89, sec. 5 sets the penalty for violations of sections one to four C at a forfeiture of not more than one hundred dollars, on a complaint made within three months of the offense. Separate insurance and driving-record consequences can follow from the citation independently of the fine.

Q: If I was lane splitting when a car hit me, can I still recover anything? A: Possibly. Under M.G.L. c. 231, sec. 85, a statutory violation is evidence of negligence but does not bar recovery on its own. Damages are reduced in proportion to the injured person’s share of fault, and recovery is barred only if that share is greater than the combined fault of the parties being sued. Every case turns on its own facts, and nothing here predicts an outcome in any particular case.

Q: The other driver says I came up between the cars, and I did not. What helps? A: Physical evidence and independent accounts, gathered early. Scene photographs, the resting positions of the vehicles, the location and direction of contact damage, witness contact information, and any nearby camera footage. Footage from businesses and dash cameras is often overwritten within days, so requests for it are time-sensitive.

Q: Do I have to wear a helmet on a motorcycle in Massachusetts? A: Yes. M.G.L. c. 90, sec. 7 requires protective head gear meeting the registrar’s standards for the operator and any passenger, including a passenger in a sidecar, and requires eye protection when the motorcycle has no windshield or screen.

Q: What does it cost to talk to a lawyer about a motorcycle crash? A: The first telephone consultation with Jim Glaser Law is free. Personal injury matters are commonly handled on a contingent fee, meaning the fee is a percentage of any recovery, and the client may still be responsible for costs and expenses. The specific fee terms are set out in a written fee agreement before any representation begins. Fee structures generally are covered in how much personal injury lawyers charge in Massachusetts.

Q: Is Jimmy Knows AI giving me legal advice? A: No. This is general information about Massachusetts law, not legal advice, and reading it does not create an attorney-client relationship. Statutes change and the way a rule applies depends entirely on the facts of a specific situation. For advice about a specific matter, speak with a Massachusetts attorney. The Jim Glaser Law line is answered 24 hours a day at (617) JIM-WINS, and the first telephone consultation is free.