Lane splitting, lane sharing, white lining and filtering forward are different names for the motorcyclist practice of using the space between traffic lanes during a traffic jam. Rather than wait behind a car or truck stopped in traffic, bikers will sometimes ride the area between traffic lanes to maneuver through and around traffic.
This practice is commonplace in Europe and permitted in areas where traffic is especially heavy. Lane splitting is not favored in the United States; California is the only state that permits it to some degree. Other states either outlaw it specifically or prosecute lane splitters using other relevant portions of the motor vehicle code.
California's position in this matter is far from clear. According the California Highway Patrol's Website, "Lane splitting by motorcyclists is permissible, but must be done in a safe and prudent manner." And therein lies the problem - what constitutes "a safe and prudent manner" is decided by the trooper on the scene. Bikers have little chance of convincing a judge that they were operating prudently if the citing officer is testifying to the contrary. Therefore, whether one can legally lane split in California depends upon what trooper is on the scene at the time.
Does Lane Splitting Cause More Accidents?
Opponents of lane splitting contend that it is a dangerous procedure that causes more motorcycle accidents. While this may seem intuitive to the driver of a vehicle who is surprised by a motorcycle at his elbow, no research to date supports this contention.
Supporters contend that lane splitting actually improves motorcycle safety. Pointing to the Hurt Report of 1981 (which didn't directly discuss lane sharing), there is evidence that the percentage of fatalities from rear-end collisions into motorcycles at that time were lower in California than other states that didn't tolerate lane splitting. Motorcyclists claim that this is because of lane splitting since fewer motorcycles are sitting in traffic in a position to be rear-ended.
The Oregon Department of Transportation recently reviewed current research efforts regarding lane sharing. The conclusion reached was that more research was needed to determine whether lane sharing should be allowed in additional states.
