It's a common sight on California roadways: Motorcycles speeding between lanes of cars to get ahead of traffic. Advantageous to riders and annoying to drivers, lane splitting has long enjoyed a legal limbo, in part because of a lack of rules around how and when to do it.
But that could soon change. On Thursday, the California State Assembly unanimously approved the lane-splitting bill AB 51, paving the way for California to become the first state in the nation to formalize the practice of lane splitting.
There is currently no law in the state that specifically allows or prevents lane splitting. The practice, however, is widely condoned by motor officers, many of whom do it themselves.
If AB 51 is signed in to law by Governor Jerry Brown, it would add a new lane-splitting section to the California vehicle code. It would also authorize the California Highway Patrol to develop educational guidelines for motorcyclists on how to split lanes in a way that's safe not only for riders but for drivers and passengers of surrounding vehicles.
It also defines lane splitting as “driving a motorcycle … that has two wheels in contact with the ground, between rows of stopped or moving vehicles in the same lane including on both divided and undivided streets, roads, or highways. ”
In 2013, the California Highway Patrol published lane-splitting guidelines on its web site to dispel misinformation, but they were retracted when someone complained that the CHP shouldn't be creating public policy, thus AB 51.
The 2013 guidelines advised motorcyclists to:
- travel no more than 10 mph faster than other traffic;
- refrain from splitting lanes when traffic is flowing 30 mph or faster;
- restrict lane splitting to the space between the first and second lanes;
- and consider the variables that may impact their ability to safely lane split, i.e. the width of traffic lanes, the size of surrounding vehicles, road conditions and the weather.
Whether the new guidelines created under AB 51 would mirror those issued by the CHP in 2013 is unclear. AB 51 requires the CHP develop lane-splitting guidelines with four other agencies — the Department of Motor Vehicles, the Department of Transportation, the Office of Traffic Safety and a motorcycle safety group.
The stated goal of AB 51 is to reduce traffic congestion and improve traffic safety. According to the Office of Traffic Safety, 87% of California motorcyclists split lanes. Common reasons for motorcyclists include getting to their destinations more quickly, keeping their motorcycles cool and keeping themselves cool, since it can be hot to sit in traffic in full safety gear on a hot day. Fatigue is often a contributing factor in motorcycle crashes.
Sue Carpenter is co-host of The Ride, Southern California Public Radio's series on modern mobility.