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"Lane filtering" becomes legal in Montana on October 1st

motorcycles in traffic.jpg
"Lane filtering" by motorcyclists in Montana signed into law
Posted at 10:19 PM, Sep 29, 2021
and last updated 2021-09-30 12:05:04-04

BILLINGS — Beginning Friday, October 1, lane filtering will become legal for motorcyclists in Montana, which experts say will ease traffic congestion but could make motorcycle riding more dangerous.

“The law is very simple, very short. It basically authorizes motorcycles to overtake and pass vehicles that are either stopped or traveling at 10 miles per hour or less in the same lane,” said Rich St. John, the Billings chief of police.

Senate Bill 9 allows drivers of two-wheeled motorcycles to overtake stopped or slow-moving vehicles at a speed not greater than 20 miles per hour, in order to "filter" between lanes of stopped traffic traveling in the same direction as conditions permit.

The bill specifies "reasonable and prudent" driving by motorcyclists when lane filtering. The law also states that motorcycles can't travel over 20 miles per hour while passing the slower moving or stopped traffic.

Lawmakers passed the bill hoping to make roads safer for motorcyclists while in stop-and-go traffic while also hoping to ease traffic congestion.

“One of the worst accidents for a motorcycle is in slower or stopped traffic if they’re the last vehicle in line. A lot of people don’t necessarily see the motorcycle taillights, they see the car lights and they come up and rear-end the motorcycle. This allows motorcycles to move in front so they're not the last vehicle when the traffic is either stopped or going slowed than 10 miles per hour,” said Rep. Barry Usher, the Billings Republican who co-sponsored the bill that passed in the 2021 Legislature.

Montana will become only the third state to make lane filtering legal. The other two are California and Utah.

Some people do have concerns about the safety of lane filtering.

“If we’re going to have some passing on the left or right in the same lane, then I fear that we’re going to have some situations where the drivers do not see the motorcycles overtaking, and we may have an incident,” said St. John.

“I wonder about people maybe not knowing about it and maybe a little road rage when motorcycles are passing you. That’s my number one concern is how other people might take it. Or some street racer might go zooming by at 30 miles per hour, so I'm a little concerned about the safety of it,” said Chuck Osborne, a motorcyclist with more than 20 years of experience.

Osborne added that he might consider lane filtering when traffic is congested, but that it's hard to do on wider motorcycles.

“I think with some education, with some responsible driving specifically by the motorcycle riders with some respectful behavior on both sides that we’ll be able to make sure this thing works like it’s supposed to,” said St. John.

Police are asking both drivers and motorcyclists to be cautious while lane filtering is happening.