Riding a motorcycle between two lanes of stopped or slowly moving traffic – a tactic known as lane splitting – is a relatively safe maneuver when both the motorcyclist and nearby drivers know the law and adhere to “safe and prudent” practices, according to two California studies released this week.
One report is a crash study that examined nearly 8,000 motorcyclists who were involved in crashes while lane splitting between June 2012 and August 2013. The second report examined lane-splitting habits among various groups in 2012 and 2013. California has more than 800,000 registered motorcycles.
“We compared the proportion of collision-involved, lane-splitting motorcyclists with injury across several body regions by whether the lane-splitting was done only in traffic flowing at 30 mph or less and that the motorcycle speed should exceed the traffic speed by no more than 10 mph,” the crash study stated.
“We found that the proportion with each injury type was high when the lane-splitting was consistent with neither speed component, was lower when it was consistent with one speed component, and was lower still when it was consistent with both speed components.”
The speed components mentioned in the report closely align with the lane-splitting guidelines posted on the California Highway Patrol website in 2013 and removed this summer after a complaint from one Sacramento resident.
“These findings bolster the position of motorcyclists and traffic-safety officials that responsible lane splitting is a safe and effective tactic for riders, particularly in heavily congested areas,” said Wayne Allard, vice president of government relations for the American Motorcyclist Association. “The AMA endorses these practices and will assist groups and individuals working to bring legal lane splitting or filtering to their states.”
California is the only U.S. state where lane splitting is permitted. State law neither prohibits nor specifically allows the maneuver.
In many countries, lane splitting and filtering are normal practices for motorcyclists, Allard said. Particularly in the highly urbanized areas of Europe and Asia, motorcycle and scooter operators are expected to pass between conventional vehicles and advance to the front of the group.
Among the findings in the California studies:
- Lane-splitting riders (2.7 percent of crashes) were less likely to be rear-ended by another vehicle than were other motorcyclists (4.6 percent);
- Lane-splitting motorcyclists involved in crashes were notably less likely than other motorcyclists in crashes to suffer head injury (9.1 percent vs. 16.5 percent), torso injury (18.6 percent vs. 27.3 percent), or fatal injury (1.4 percent vs. 3.1 percent) than other motorcyclists.
- The proportion of motorcyclists with a head injury was 6.3 percent for those lane-splitting consistent with the “safe and prudent” traffic speed guidelines, 10.7 percent for those lane-splitting in traffic flowing at 30 mph or less but exceeding the traffic speed by more than 10 mph, 9 percent for those lane-splitting in traffic flowing faster than 30 mph but exceeding traffic speed by less than 10 mph, and 20.5 percent for those who were lane-splitting in traffic flowing at more than 30 mph and who were exceeding traffic speed by more than 10 mph.
“Motorcyclists who oppose lane splitting should remember that it is optional in California,” Allard said. “Permitting lane splitting is not the same as requiring it. So those opposed to the practice should consider the desires of other motorcyclists who believe they would benefit from it. Lane splitting is an issue of choice.”
The California studies are Safety Implications Of Lane-Splitting Among California Motorcyclists Involved In Collisions by Thomas Rice and Lara Troszak of the Safe Transportation Research & Education Center (SafeTREC) at the University of California Berkeley, and the Motorcycle Lane-Share Study Among California Motorcyclists And Drivers 2014 And Comparison To 2012 And 2013 Data conducted by Ewald & Wasserman Research Consultants, LLC, on behalf of the California Office of Traffic Safety and SafeTREC.
The goal of the project was to obtain information not usually collected during law enforcement investigations of motorcycle traffic collisions in California. The reports are the result of a two-year collaboration between SafeTREC and the California Highway Patrol. The California Office of Traffic Safety provided funding.
The data came from collision investigations by CHP officers and by officers at more than 80 allied law enforcement agencies in the state.