Montana Gov. Greg Gianforte has signed SB 9, which will allow motorcycles to filter through stopped and slow-moving vehicles beginning on October 1. Two Montana Republicans—state Sen. Russ Tempel and state Rep. Barry Usher—sponsored SB 9. Republican state senators voted 27-2 in favor of the bill, while Democrat state senators opposed it by a 16-2 margin.
Not to be confused with lane-splitting, which is legal in California and allows motorcycles to pass between moving vehicles at higher rates of speed, the Montana bill only allows passing vehicles moving no more than 10 mph. The motorcycle cannot exceed 20 mph while filtering.
Here is the text of the legislation:
SB 9 Section 1. Lane filtering for motorcycles.
(1) An operator of a two-wheeled motorcycle may engage in lane filtering when:
(a) the operator of a two-wheeled motorcycle is on a road with lanes wide enough to pass safely;
(b) the overtaking motorcycle is not operated at a speed in excess of 20 miles an hour when overtaking the stopped or slow-moving vehicle; and
(c) conditions permit continued reasonable and prudent operation of the motorcycle while lane filtering.
(2) As used in this section, “lane filtering” means the act of overtaking and passing another vehicle that is stopped or traveling at a speed not in excess of 10 miles an hour in the same direction of travel and in the same lane.
Russ Ehnes, chair of the AMA Board of Directors, was present at the SB 9’s signing, saying, “We applaud the efforts of Montana’s motorcycling community and the state’s legislators, and thank Gov. Gianforte for signing this legislation into law.”
“With the signing of SB 9,” AMA On-Highway Government Relations Manager Tiffany Cipoletti noted, “Montanans have recognized the benefits of lane splitting, which allows motorcyclists the choice to filter in traffic when it is safe to do so. As lane-splitting support continues to gain traction across the country, I am eager to help more motorcyclists engage their state legislatures on this issue.”
A UC Berkeley study confirmed that filtering is less dangerous for motorcyclists than being stopped in traffic. California and Utah allow filtering, with 47 states still prohibiting the safer riding behavior.