Arizona's lane filtering law, explained

What the law says

Section 28-903 of the Arizona Revised Statutes sets Arizona’s rules for motorcycles passing within and riding between lanes. Riding between lanes is often called lane splitting, and doing it past stopped traffic is often called lane filtering.

The section starts by protecting riders. Under section 28-903(A) of the Arizona Revised Statutes, every motorcycle is entitled to the full use of a lane, and no one may drive a vehicle in a way that takes that from a motorcycle. That rule does not apply to motorcycles riding two abreast, meaning side by side, in one lane.

Then come the general bans. Except as subsection F allows, a rider may not pass a vehicle in the same lane, under section 28-903(B) of the Arizona Revised Statutes. Also except as subsection F allows, a rider may not ride between lanes of traffic or between rows of vehicles, under subsection C. And under subsection D, no more than two motorcycles may ride side by side in one lane.

The statute uses neither term. Subsection F allows both, within limits: it lets the rider of a two-wheeled motorcycle do two things, under the Arizona Revised Statutes:

“may overtake and pass another vehicle that is stopped in the same direction of travel and in the same lane as the operator and may operate the motorcycle between lanes of traffic if the movement may be made safely”

The permission comes with conditions, and all of them must be met under section 28-903(F) of the Arizona Revised Statutes. The motorcycle must have two wheels. The move must be safe. The street must have at least 2 lanes next to each other going the same way.

The street’s speed limit must be no more than 45 miles per hour. And the rider must travel no faster than 15 miles per hour while doing it, according to section 28-903(F) of the Arizona Revised Statutes.

Police officers on duty are exempt from the passing and lane rules in subsections B and C, under section 28-903(E) of the Arizona Revised Statutes.

What changes the answer

The kind of road. On a street with only 1 lane in the rider’s direction, or with a speed limit above 45 miles per hour, subsection F of section 28-903 does not apply. The general ban in subsections B and C of the Arizona Revised Statutes then stands.

The rider’s speed. Moving between lanes at more than 15 miles per hour falls outside section 28-903(F) of the Arizona Revised Statutes, even on a street that qualifies.

The number of wheels. Subsection F covers a two-wheeled motorcycle. A motorcycle with 3 wheels is outside it, so the general ban in section 28-903 of the Arizona Revised Statutes applies to it.

Whether traffic is stopped. The passing permission covers a vehicle that is stopped in the same lane. Passing a moving vehicle in the same lane is still banned by section 28-903(B) of the Arizona Revised Statutes.

Safety. Even when every other condition is met, section 28-903(F) of the Arizona Revised Statutes allows the move only if it can be made safely.

Breaking the rule. A violation of section 28-903 is a civil traffic violation, not a crime. The section sits in chapter 3 of Title 28, according to the index of the Arizona Revised Statutes. As a rule, section 28-121 of the Arizona Revised Statutes makes a violation of Title 28 a class 2 misdemeanor, but a violation of chapter 3 is a civil traffic violation unless the statute that defines it says otherwise, and section 28-903 does not.

The penalty. Under section 28-121, civil traffic violations follow articles 3 and 4 of chapter 5, and the index of the Arizona Revised Statutes places section 28-1598 in article 4. Section 28-1598 of the Arizona Revised Statutes caps the civil penalty at $250, except as otherwise provided. The court also levies surcharges under sections 12-116.01 and 12-116.02, which this page did not read.

Riding side by side. Two motorcycles may share one lane, but three may not, under section 28-903(D) of the Arizona Revised Statutes. The full-lane protection in subsection A does not cover motorcycles riding two abreast.