California Legislators Put Lane-Splitting Bill AB51 On Hold

The controversial bill that recently passed the state Assembly has been tabled for 2015.

Lane splitting
Bill AB51, if passed, would make it legal to lane-split but would also impose strict rules for doing so.Brian Hatano

According to a report from the Motorcycle Industry Council (MIC), the California bill AB51 that passed the state assembly in May 2015 has been withdrawn for 2015. Since the practice of riding between lanes in California falls into a legal gray area, motorcyclists continue to filter through traffic with little or no opposition from law enforcement agencies. Bill AB51, if passed, would make it legal to lane-split but would also impose strict rules for doing so. Law enforcement agencies favor AB51 while the American Motorcyclist Association is against the strict rules.

The following is a quote from the MIC:

“Pending California lane-splitting legislation has been tabled for 2015. The bill's sponsor learned of concerns within Governor’s office on how the bill would be implemented; rather than facing a potential veto, the sponsor has decided to hold the bill in committee until 2016. His office will continue to engage with rider groups, California Highway Patrol, Department of Transportation and the Department of Motor Vehicles during the fall and into next year. The bill has passed the Assembly."

The Motorcycle Industry Council's Position On Lane-Splitting
Lane-splitting (also called "lane sharing") refers to the technique of riding a motorcycle between two adjacent lanes of traffic heading in the same direction. Currently, California is the only state in which lane-splitting is legal and it is widely practiced by motorcyclists in the state. Many motorcyclists embrace the technique because it gives them the option to pass slow-moving or stopped traffic, whether on a highway or multi-lane city street, and other motorists may appreciate the reduced congestion since the motorcyclist is not taking up space with an automobile in the traffic lanes.

Other potential benefits include an increase in conspicuity since the motorcyclist is moving relative to other traffic; a reduction in motorcyclist fatigue from constant shifting and braking in traffic, since the vast majority of motorcycles have a manual transmission; a reduction in the motorcyclist's exposure to ambient heat in the summer and car exhaust year-round; and a reduction of engine damage from extended idling, especially for models with air-cooled engines.

Critics of the technique cite the possibility of a car changing lanes, cutting off the motorcyclist and causing a collision. However, most riders will only split lanes when traffic is moving slowly, limiting the speed at which a driver can make a lateral move and giving the rider ample opportunity to avoid a collision.

A study published in May 2015, Motorcycle Lane-splitting and Safety in California, conducted by researchers from the Safe Transportation Research and Education Center at the University of California Berkeley found that lane-splitting is relatively safe if done in traffic moving at 50 mph or less, and if motorcyclists do not exceed the speed of other vehicles by more than 15 mph. The researchers analyzed data on motorcycle-involved traffic collisions in California from June 2012 through August 2013. Of the nearly 6,000 collision-involved motorcyclists studied, 997 were lane-splitting at the time of their collision. When motorcyclists who were lane-splitting were compared with those who were not, lane-splitting motorcyclists were much less often injured during their collisions. They also were considerably less likely to suffer head injury (9 percent versus 17 percent), torso injury (19 percent versus 29 percent) and fatal injury (1.2 percent versus 3 percent) than riders who were not lane-splitting. The study found that motorcycle speed differential is a stronger predictor of injury than was the overall traffic speed. Speed differentials of up to 15 mph were not associated with changes in injury occurrence; a speed differential above 15 mph was associated with increases in the likelihood of injury of each type.

Another study, "Motorcycle Lane Splitting on California Freeways," James V. Ouellet, 2011, suggests that lane-splitting is no more hazardous than maintaining a normal lane position, because a car driver might sideswipe a motorcyclist or cross the motorcyclist's path whether the rider is situated within a lane or between lanes. The Ouellet study also cites Los Angeles and European research in suggesting that lane-splitting may even be safer, since motorcyclists are less likely to be rear-ended in stop-and-go traffic while splitting than while in a normal lane position. Riders can manage the risks of lane-splitting by being extra cautious and alert and following a few common-sense guidelines:

  1. Only split between the two left-most traffic lanes. This consistency of location helps car drivers in those lanes learn to expect motorcyclists.
  2. Only split when there is ample space between the lines of cars.
  3. Do not split lanes when traffic is at or near the speed limit. The goal of splitting lanes is to keep moving at a reasonable speed through slow or stopped traffic, not to pass cars that are already moving at reasonable speeds.
  4. Do not ride substantially faster than the adjacent lines of cars, and never exceed the speed limit. To minimize risk, the speed differential between the motorcyclist and surrounding traffic should be kept to a reasonable level.
  5. Use the carpool lane (if present) instead of splitting lanes, if the traffic in the carpool lane is flowing freely. The limited-access nature of carpool lanes generally makes this a safer choice for motorcyclists. It is legal throughout the U.S. for a solo motorcyclist to use carpool lanes.
  6. You can share the carpool lane (if present) with other vehicles, but be alert for cars crossing your path at entry and exit points.
  7. Avoid riding on the double yellow line and never cross the double yellow line that separates the carpool lane from regular traffic lanes.

The best assessment strategy for a motorcyclist to use in all situations is what the Motorcycle Safety Foundation recommends – SEE: Search, Evaluate, Execute. This strategy helps riders minimize risk by detecting and avoiding potentially hazardous traffic situations, managing time and space cushions, and identifying escape paths. Some riders also use the strategy of assuming they're invisible to other motorists, because other motorists may not be on the lookout for motorcycles.

In full consideration of the risks and benefits of lane-splitting, the Motorcycle Industry Council supports state laws that allow lane-splitting under reasonable restrictions.