Wisconsin Lane Splitting: No Statute, and the Full-Lane Rule Blocks It

Section 346.595, headed "Motorcycles and mopeds", is the only section of the Wisconsin statutes devoted to how a motorcycle is ridden. Its six subsections cover lane entitlement and riding two abreast, side-saddle riding, foot rests and who may ride as a passenger, the two-person limit unless a sidecar is fitted, passengers in front of the operator, headlamps lit whenever the motorcycle is in operation, and moped lane position. Not one of them mentions passing between lanes, riding the painted line, or moving between rows of stopped traffic. A full-text scan of chs. 340 through 351 returns zero occurrences of the phrase, so the answer in Wisconsin is not that splitting is a named offence, and not that it is authorised, but that it is governed by the general rules.

The operative sentence cuts both ways. All motor vehicles including motorcycles and mopeds are entitled to the full use of a traffic lane, and no vehicle may be driven or operated in such a manner as to deprive any other vehicle of the full use of a traffic lane. A driver who crowds a rider toward the fog line violates it. So does a rider travelling up the boundary between two occupied lanes, because a machine straddling the line is taking part of the lane that the vehicle beside it is entitled to use in full.

The charge an officer actually writes is usually the general lane-discipline rule. Section 346.13 (1) requires the operator of a vehicle to drive as nearly as practicable entirely within a single lane and not to deviate from that lane without first ascertaining that the movement can be made with safety to other vehicles approaching from the rear. The Department of Transportation assesses 4 demerit points for "Deviating from lane of traffic" under s. Trans 101.02 (2) (a), and 12 points accumulated for violations committed within any 12-month period suspends the operating privilege under s. Trans 101.04 (1).

The passing rules close the other route. Section 346.07 (2) requires an overtaking driver to pass to the left at a safe distance and to stay left until safely clear of the overtaken vehicle. Section 346.08 permits passing on the right only under conditions permitting the movement in safety, only if the operator can do so while remaining on either the roadway or a paved shoulder, and then only in three situations: the overtaken vehicle is making or about to make a left turn or U-turn; the pavement is unobstructed and wide enough to enable two or more lines of vehicles lawfully to proceed in the same direction at the same time; or the road is one-way or divided and unobstructed pavement is wide enough for the same. A rider filtering up the right-hand side of a queue inside a single lane meets none of them, because one lane is not two lines of vehicles lawfully proceeding.

What Wisconsin does allow is worth knowing precisely, because it is unusual. Two motorcycles may ride abreast in one lane, and the statute conditions that on the consent of both drivers rather than leaving it to custom. Mopeds get the same allowance only where the posted limit is 25 miles per hour or less, and under s. 346.595 (6) a moped on any road posted above 25 must be ridden single file in the extreme right-hand lane and may not be operated on a restricted-access highway at all.

Wisconsin also legislates motorcycle space sharing when the machines are stopped, which shows the legislature knows how to grant it when it wants to. Section 346.54 (1) (cm) lets a motorcycle or moped park at an angle in a parallel parking area, requires 2 feet of clearance from another vehicle where no markings exist, and allows up to 3 motorcycles or mopeds in a marked parallel space, an authorised angle space, or a metered space unless a sign or pavement marking restricts that space to one machine. Each rider in a shared metered space receives a separate citation for a time violation. Nothing comparable was written for a moving traffic lane.

Which forfeiture applies depends on the section the officer cites. A deviating-from-lane citation under s. 13 (1) carries a forfeiture of not less than $20 nor more than $40 for a first offence and not less than $50 nor more than $100 for a second or subsequent conviction within a year under s. 17 (1), and 4 demerit points. An improper pass under s. 07 (2) or s. 08 carries not less than $30 nor more than $300 under s. 17 (2), and "Passing illegally" is a 3 demerit point violation under s.

02 (3) (L). A violation of s. 595 itself, including riding more than two abreast in a lane or riding two abreast without the other rider's consent, carries not less than $30 nor more than $300 under s. 60 (4). Points stack across all three, and 12 in any 12-month period costs the licence. Because Wisconsin has no lane-splitting statute, there is also no statutory defence to plead: a rider cannot point to a speed differential cap or a stopped-traffic exception of the kind other states have written, and a crash while splitting invites the argument that the rider deprived another vehicle of the full use of its lane.