Rules of the Road: Is lane-splitting actually a safer option for motorcycles?
Q: I’ve seen studies showing that lane-splitting is safer for motorcyclists, so why isn’t it legal in Washington? They’ve been doing it for years in California.
A: To paraphrase Inigo Montoya in “The Princess Bride”: “You keep using that study. I do not think it means what you think it means.” Don’t take this as criticism, but have you read the studies you mentioned, or have you read articles about the studies? I won’t judge you if it’s the latter; research studies are long and boring. We rely on journalists to make them short and interesting.
But sometimes that leads to misinformation. Take, for example this headline: “Study Finds Lane-Splitting Increases Rider Safety” (written by an organization that endorses lane-splitting). Meanwhile, the authors of the study directly contradict that headline, saying, “The current data set cannot be used to compare the collision risks for lane-splitting or non-lane-splitting riders.”
This study seems to be the one most often referenced to support lane-splitting (probably because other studies show things like lane-splitting riders are four times more likely to crash, and lane-splitting reduces situational awareness). When used to advocate for lane-splitting, writers tend to focus on two details in the report: crashes involving lane-splitting result in fewer injuries, and riders who lane-split are less likely to be rear ended.
And if you’re reading this and asking, “What is lane-splitting?” It’s this: passing slower moving traffic by riding a motorcycle in the gap between two parallel lanes of traffic heading in the same direction. California has permitted it for decades. Minnesota began allowing it last year (at traffic speeds of 25 mph and below). There are a few states that allow lane-filtering, which is similar but with stopped traffic. Washington law prohibits it, stating “No person shall operate a motorcycle between lanes of traffic or between adjacent lines or rows of vehicles.”
Getting back to the report, it’s no surprise that a lane-splitting rider is almost half as likely to be rear-ended; it’s hard to get hit from behind if you’re going faster than surrounding traffic. The study does point out that lane-splitters are more than twice as likely to rear-end another vehicle.
But what about the fewer injuries for lane-splitters? Here’s what the study found: Compared with other motorcyclists, riders who lane-split are more likely riding during the daytime during commuting hours, they’re less likely to be impaired, and they’re wearing more protective helmets. The study also shows that few motorcyclist lane-split when the speed of traffic is above 40 mph, and when they do lane-split most riders limit their speed to within 15 mph or less than that of the traffic they’re passing. When lane-splitting riders exceeded those speeds their injury risk went up substantially.
While the report doesn’t come out and say it, I’ll make a couple observations. Given that lane-splitters tend to be commuters, they’re likely more experienced riders. Keeping passing speed-differential low shows good judgment, as does wearing the right helmet.
Even though the title of the study is “Motorcycle Lane-Splitting and Safety in California” the real takeaway is less about lane-splitting than it is about riders themselves: Experienced motorcyclists who ride sober, respect the speed limit, wear proper safety gear, and exercise good judgment decrease their risk of injury compared to other riders.
We didn’t need a study to tell us that, but when motorcyclists make up only 0.3 percent of miles traveled and 16 percent of traffic fatalities in Washington, it’s a good reminder.
This story was originally published June 15, 2026 at 5:00 AM with the headline "Rules of the Road: Is lane-splitting actually a safer option for motorcycles?."
