The O’Sullivan Law Firm, a Denver personal injury firm, is highlighting Colorado’s motorcycle lane filtering law and an upcoming deadline for the Colorado Department of Transportation to report on its safety effects. Senate Bill 24-079 requires the department to issue its report to the General Assembly by January 1, 2027, and the lane filtering provision is repealed effective September 1, 2027.
Senate Bill 24-079, Motorcycle Lane Filtering and Passing, was signed by Governor Jared Polis on April 4, 2024, and took effect August 7, 2024, according to the Colorado Department of Transportation. The signed bill amended section 42-4-1503 of the Colorado Revised Statutes.
Under the statute, the driver of a two-wheeled motorcycle may overtake or pass another motor vehicle in the same lane only if the overtaken vehicle is stopped, vehicles in adjacent lanes traveling in the same direction are stopped, the road has lanes wide enough to pass safely, the motorcycle is driving at 15 miles per hour or less, and conditions permit prudent operation. When the vehicles being passed begin moving, the driver must stop passing.
A driver passing under the law may not pass on the right shoulder, to the right of a vehicle in the farthest right-hand lane if the highway is not limited access, or in a lane of traffic moving in the opposite direction. Section 42-4-1503 continues to prohibit driving a motorcycle between lanes of traffic or between adjacent lines or rows of vehicles, except as the lane filtering provision allows.
The department must analyze data on the safety effects of the provision and report to the General Assembly by January 1, 2027. The statute says the report must include motorcycle rear-end collisions before and after the effective date, the severity of rear-end collisions in heavy traffic conditions before and after that date, and motorcycle side-swipe collisions while overtaking or passing at less than 15 miles per hour before and after that date.
The lane filtering provision is repealed effective September 1, 2027. The Colorado State Patrol has said the law repeals automatically on September 1, 2027.
In the bill’s legislative declaration, the General Assembly cited a 2009 study by the European Association of Motorcycle Manufacturers that found motorcyclists were seven times more likely to be hit while stopped than to crash while lane splitting. It determined that lane filtering at 15 miles per hour or less, when conditions permit, is in the best interests of motorist safety.
According to the Colorado Department of Transportation, 165 motorcyclists died on Colorado roads in 2024, a record, and motorcyclists accounted for 24 percent of traffic deaths while motorcycles made up 3 percent of registered vehicles. The department also reported that 15 motorcyclists died from January through March 2026, the deadliest start to a year since 2017.
The O’Sullivan Law Firm focuses on personal injury law, including motorcycle accidents, car accidents, bicycle accidents, truck accidents, pedestrian accidents, and wrongful death claims, according to the firm.
The legal information in this release is based on the signed text of Senate Bill 24-079 and statements from the Colorado Department of Transportation and the Colorado State Patrol. It is presented for general public awareness and is not legal advice. How the law applies to a particular crash depends on the facts and the law in effect on the date of the crash.
The O’Sullivan Law Firm represents injured riders in motorcycle accident cases throughout Colorado.
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For more information about The O’Sullivan Law Firm, contact the company here:
The O’Sullivan Law Firm
Scott O’Sullivan
+13033885304
scott@riderjustice.com
600 N Ogden St, Denver, CO 80218
