Massachusetts Bans Lane Splitting But Allows Two Abreast

Massachusetts puts the whole answer in a single sentence of G.L. c. 89, § 4A, a section headed "Driving vehicles in a single lane; motorcycles, riding and passing." The section opens with the general lane discipline rule that binds every driver: when a way has been divided into lanes, the driver shall drive entirely within a single lane and shall not move from that lane until he has first ascertained whether the movement can be made with safety. The motorcycle sentence then follows and sets three separate rules at once.

First, operators of motorcycles shall not ride abreast of more than one other motorcycle. That is an express statutory permission to ride two abreast in one lane, stated as a cap rather than as a grant. Three abreast is out. Massachusetts is therefore not a state where side by side riding rests on custom or on police tolerance, and a rider stopped for it can point to the text.

Second, motorcycles shall ride single file when passing. The two-abreast allowance ends at the moment of an overtake, so a pair riding side by side must fall into single file before either of them passes anything.

Third, and this is the lane splitting rule, motorcycles shall not pass any other motor vehicle within the same lane, except another motorcycle. Filtering between lanes of stopped traffic, riding the painted line past a queue on Route 128 or splitting up the inside of a backed-up tunnel approach are all covered by that prohibition. Massachusetts attached no conditions to it, which distinguishes the state sharply from the filtering regimes some other states adopted: there is no stopped-traffic condition, no fifteen or twenty-five mile per hour differential, no cap on the road's speed limit, no two-wheel-only restriction and no sunset date. The rule is the same at a standstill and at highway speed.

The exception is the part most riders miss. Because the prohibition reaches passing "any other motor vehicle within the same lane, except another motorcycle," a motorcycle may lawfully pass another motorcycle inside a single lane. Two riders sharing a lane may change their order without changing lanes. What they may not do is use the same manoeuvre against a car, a truck or a bus.

Massachusetts also has no separate authorisation anywhere in chapter 89 or chapter 90 permitting filtering, no pilot programme and no local option letting a city or town allow it. Chapter 89 is the passing and overtaking chapter, and the only motorcycle-specific text it contains is the sentence in § 4A.

One structural point matters for who is caught. The lane discipline duty in the first half of § 4A applies only where a way "has been divided into lanes." On an unmarked two-lane road with no lane lines painted, the first half of the section has nothing to bite on. The motorcycle sentence is written without that condition, so the same-lane passing ban and the two-abreast cap are not limited to marked ways.

c. c. 89, § 5, which covers sections one to four C inclusive and provides that the offender shall, upon complaint made within three months after the commission of the offense, forfeit not more than one hundred dollars. That three-month complaint deadline is a real limit: a charge brought later than three months after the incident is out of time under the section's own words. Section 5 also carries a general defence that reaches § 4A. Sections one to 4D do not apply to a person acting in conformity with the direction of a police officer, to the driver of a vehicle actually engaged in authorized work upon a highway under construction, repair or maintenance where the nature of the work requires a departure from normal practice, or to any operator where construction or repair prohibits passage in the ordinary travel lane or lanes.

A rider waved through a lane by an officer at a crash scene, or routed around a coned-off work zone, is therefore outside the section rather than relying on discretion. c. 175, § 113B.