A total of six U.S. states now allow lane filtering, the careful, precise movement of a motorcycle between two lanes of slow-moving traffic. In July of 2025, Minnesota became the latest state to make the maneuver legal, joining California, Utah, Arizona, Montana, and Colorado as the only states where bikers can lane filter without breaking the law. (Of these six, California is the only state that also allows high-speed lane splitting — and there is a difference between the two!)

But even though it’s legal in these half-dozen states, each has its own set of strict limits on how and when riders can filter. For instance, Minnesota’s law allows filtering when traffic is moving 25 mph or slower, but bikers can’t ride more than 15 mph faster than the surrounding traffic. Alternatively, Colorado says riders have to stick to 15 mph or slower while filtering, and riders can only filter between stopped vehicles traveling in the same direction. Arizona, Utah, and Montana have all passed similar measures in recent years, with their maximum speeds ranging between 10 and 45 mph.

While it might sound like an unsafe thing to do, the legalization of lane filtering is actually based on hard data that shows the practice might be making the roads safer. In fact, studies show that lane-splitting riders were less likely to suffer head, torso, or otherwise fatal injuries compared to riders who stayed in a single lane. Rear-end accidents — one of the most common hazards for motorcyclists stopped in traffic — dropped from 4.6% to 2.6% when lane splitting was put into practice. Collectively, they all point to unequivocal evidence that filtering cuts down on congestion as well as crash risks for motorcyclists.

International research supports those American conclusions. A recent European study revealed that riders were seven times more likely to be struck when stopped as opposed to filtering. A similar Australian study found zero rear-end crashes tied to lane filtering over the course of an eight-week period. It’s not hard to believe when you really think about it; lane filtering would naturally ease up on overall traffic when motorcycles occupy less space in slow-moving lines.

Even with all of this irrefutable data, lane filtering being legal in just six states out of fifty means this research is far from being universally (much less nationally) recognized as fact. Critics argue that U.S. roadways were not designed with lane filtering in mind, and modern cars — which are much wider than in past decades — leave increasingly little margin for error. Going forward, more public education campaigns could be the key to countering these arguments and standardizing the proven benefits of lane filtering.

It worked for Minnesota: They set aside $200,000 for this exact purpose, and now lane filtering is legal in the state. In the meantime, lawmakers in at least eight other states (including Oregon, Texas, and Virginia) are considering the legalization of lane filtering. For now, the fact remains: only half a dozen states have officially made the move.