Lane Splitting Will Soon Be Legal for Motorcyclists in Montana

On March 3, 2021, Montana became only the 3rd state to legalize lane splitting when Greg Gianforte signed Senate Bill 9 into law. The new law goes into effect on October 1, 2021.

Lane splitting, which refers generally to a motorcyclist traveling between 2 lanes of traffic that are headed in the same direction, is one of the most controversial and misunderstood actions.

Let’s take a closer look at lane splitting and Montana’s new lane-splitting law.

What is lane splitting?

Lane splitting (also called “stripe riding” or “filtering”) is when a motorcyclist rides between 2 lanes of traffic heading in the same direction. Lane splitting generally occurs when traffic slows on a highway, but some motorcyclists split lanes in order to filter to the front of traffic at a stoplight.

Motorcycle groups, including the American Motorcyclist Association, have long advocated that motorcyclists who split lanes in heavy traffic are significantly less likely to be struck from behind by other motorists.

“Perhaps one of the most dangerous situations for any on-highway motorcyclist is being caught in congested traffic, where stop-and-go vehicles, distracted and inattentive vehicle operators, and environmental conditions pose an increased risk of physical contact with another vehicle or hazard. Even minor contact under such conditions can be disastrous for motorcyclists.”

Most research has found lane splitting to be beneficial. 

A study conducted by the Safe Transportation Research & Education Center at the University of California Berkeley found that:

• Lane-splitting riders were significantly less likely to be rear-ended than non lane-splitting riders, and
• Lane-splitting riders were markedly less likely to suffer a head injury, torso injury, or fatal injury than non-lane-splitting motorcyclists.

However, critics of lane splitting argue that motorcyclists ride aggressively between cars in ways that scare drivers and create dangerous situations, such as when a car attempts to switch lanes.

Overview of Montana’s new lane-splitting law

Historically, lane splitting was never mentioned in Montana’s laws. However, on March 2, 2021, Montana became only the 3rd state (Utah and California are the others) to explicitly legalize lane splitting under certain conditions.

Montana Senate Bill 9, which goes into effect October 1, 2021, says that motorcyclists are allowed to lane-split when:

• The lanes are wide enough to pass safely,
• The motorcycle is not operated at a speed in excess of 20 miles an hour, and
• The conditions (road, weather, etc.) permit continued reasonable and prudent operation of the motorcycle while lane splitting.

“With the signing of S.B. 9, Montanans have recognized the benefits of lane splitting, which allows motorcyclists the choice to filter in traffic when it is safe to do so,” said Tiffany Cipoletti, on-highway government relations manager for the American Motorcyclist Association.

Lane-splitting safety tips

Whether or not lane splitting is safe depends largely on how it’s done.

Montana’s law requires motorcyclists to take certain safety precautions, as lane splitting is only permitted when there’s enough room to pass safely, the motorcyclist is traveling 20 mph or less, and the conditions are safe.

Research indicates that riders should travel even less than 20 mph in certain situations. For example, a yearlong study concluded that lane splitting is no more dangerous than riding a motorcycle 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 mph faster than the traffic the motorcyclist is passing.

Other lane-splitting safety tips include:

1. Always leave yourself a little extra space. It’s often car mirrors that knock lane-splitting motorcyclists down.
2. Keep your fingers on the brake and clutch. You need to be ready to react immediately when someone pulls in front of you.
3. Maintain a straight line when possible. Weaving could confuse drivers and cause them to overcorrect. 
4. Watch out for other motorcyclists jumping into the channel. Pay special attention to large vehicles that might block you from seeing a motorcyclist slide in front of them.
5. Respect turn signals. If a driver has a turn signal on, don’t try to speed up to pass the vehicle before it switches lanes.
6. If you’re riding between 2 lanes and one lane slows down while the other continues, be prepared for cars to swerve from the slow lane to the faster lane.
7. Always wear proper gear. Proper gear includes a full-face helmet, motorcycle jacket and pants, and above-ankle motorcycle boots.
8. Don’t lane split around curves.
9. Avoid lingering in blind spots.
10. Keep in mind that poor visibility (due to darkness, rain, fog, etc.) makes it more difficult to see what other drivers are doing, and makes it more difficult for other drivers to see what you’re doing.