Gov. Jerry Brown signed legislation Friday that takes a step toward condoning the practice of lane-splitting, in which motorcyclists drive between two lanes of vehicles.
The Democratic governor's signature allows the California Highway Patrol to develop guidelines, but the bill stops short of explicitly authorizing the practice.
Lane-splitting is in a legal grey area in California, not mentioned in law but tolerated by law enforcement. The CHP published educational guidelines on lane-splitting in 2013, but regulators later ruled the agency had no authority to make public policy.
The Assembly voted in May to explicitly allow it with a 50-mph speed limit, but the Senate watered down the bill before approving it unanimously.
Lane-splitting is a controversial practice that ignites passions on both sides. While some drivers are spooked by the sudden appearance of motorcycles out their window, motorcyclists say it is a safe and efficient way to move through California's notoriously heavy traffic.
California is the only state to allow lane-splitting, and motorcyclists worried that authorities would someday begin ticketing drivers if the practice were not specifically mentioned in state law.
"The California Highway Patrol has had an excellent set of guidelines for lane-splitting, and working with them, we're certain that those guidelines will be reinstated," said Pete terHorst, a spokesman for the American Motorcyclist Association.
The CHP guidelines advised motorcyclists to travel no more than 10 mph faster than traffic and to only do it when surrounding vehicles were traveling at 30 mph or less, among other suggestions.
The bill was written by Assemblyman Bill Quirk, a Hayward Democrat, and Tom Lackey, a Palmdale Republican.