“Lane splitting” or “lane filtering” will be legal in Montana beginning Oct. 1, 2021.
Governor Greg Gianforte signed a bill in March to make 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.
Montana will be the third state to define such maneuvers as legal, in addition to California and Utah.
The exact text of the bill can be seen below:
AN ACT PROVIDING FOR MOTORCYCLE LANE FILTERING.
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.