Motorcycle lane-splitting study finds: the more speed, the more danger

A year-long California study of motorcycle lane-splitting has concluded the practice is no more dangerous than motorcycling in general, if the rider is traveling at speeds similar to or only slightly faster than the surrounding traffic.

The maneuver becomes more dangerous, however, when a motorcyclist is speeding or riding more than 10 miles per hour faster than the traffic the cyclist is passing.

Lane-splitting occurs when a motorcyclist passes other vehicles by riding between them along the lane line. California is the only state that does not ban the controversial practice, frowned on by many car drivers who consider it a safety hazard, and applauded by some motorcyclists who say they consider lane-splitting a safety tool that allows them to get out of risky situations.

Lane-splitting in California appears to be on the rise. The state Office of Traffic Safety study found 62 percent of motorcyclists say they lane-split on both freeways and other roads, a 7.5 increase over 2013. Seventy-five percent of riders between the ages of 18 and 24 report they lane-split on all roads, including freeways. Notably, the survey found that motorcyclists were splitting lanes at slightly slower speeds and in slightly slower traffic than the year before.

The lane-splitting crash study, conducted by the University of California, Berkeley, and commissioned by the California Highway Patrol and the state Office of Traffic Safety, also found that lane-splitters are less likely to be rear-ended by car drivers, but are more likely to rear-end other vehicles.

Lane-splitters had a greater chance of being involved in a crash during the morning and afternoon commute hours than motorcyclists who were not lane splitting. The study also found that lane-splitting cyclists who were involved in crashes typically wore safer helmets than motorcyclists as a whole.

“What we learned is, if you lane-split in a safe or prudent manner, it is no more dangerous than motorcycling in any other circumstance,” state Office of Traffic Safety spokesman Chris Cochran said. “If you are speeding or have a wide speed differential (with other traffic), that is where the fatalities came about.”

The study was conducted statewide by 80 law enforcement agencies who filled out a supplemental information sheet involving 8,262 motorcycle riders in collisions.

The study’s authors said the report, the first of its kind about lane-splitting, is limited in scope, and will be followed up by more detailed analysis, including looking at rider age, rider gender, motorcycle characteristics, and collision and roadway characteristics.

The CHP last year published written guidelines on when motorcyclists should or should not lane-split, suggesting riders should not travel more than 10 miles per hour faster than surrounding traffic, and should not lane-split at all if other vehicles are traveling faster than 30 miles per hour. The CHP took those guidelines down, however, after a disagreement over whether publishing them constituted illegal regulations.

Call The Bee’s Tony Bizjak, (916) 321-1059.