Important laws to help cyclists and drivers arrive safely to their destinations

Boulder County, Colo. - Safety on the road is about following rules and recognizing the humanity of everyone. Here are a few important laws to help cyclists and drivers arrive safely to their destinations.

Driver and Cyclist Laws

• View the Colorado Driver Handbook (PDF).
• Drivers must keep a minimum of three feet between the vehicle, including mirrors, and the cyclist.
• Cyclists can ride two abreast as long as they do not impede the normal flow of traffic.
• Drivers yield by waiting for cyclists who temporarily may not be able to ride fully to the right.
• Cyclists ride as far to the right as practicable based on hazards, passing slower vehicles, or the need to take the lane to turn left or similar.
• Drivers do not pass a cyclist without sufficient sight distance of the road and/or remain behind a cyclist when approaching an intersection or railroad crossing.
• Drivers may only use a cell phone or device while it is in hands-free mode. View information on the Colorado Hands Free Law.
• Yield to other, slower drivers in front of them who may be lawfully slowing and/or yielding to cyclists, pedestrians, or equestrians. It is illegal to fail to yield the right-of-way, and other aggressive or intimidating actions could constitute a crime.
• Drivers may cross a double yellow centerline to pass a cyclist (while keeping a minimum of three feet between the outermost projection of one’s vehicle and the cyclist) only if it is safe to do so. Do not pass cyclists on blind curves.
• Drive the speed limit. Drivers going too fast is the leading factor in most traffic deaths.
• To report aggressive, illegal or dangerous road use dial *277 for the Colorado State Patrol.

Drivers in Colorado must give at least three feet of space when passing a bicycle. Crossing a double yellow line to pass is permissible, but only when safe to do so.

Cyclist Laws

• Cyclists are required to ride with a white headlight and a rear red reflector between dusk and dawn or during periods of low visibility.
• Cyclists cannot impede normal traffic flow, defined as holding up five or more vehicles behind a cyclist.
• The Colorado Safety Stop permits a cyclist who is 15 years of age or older to treat a stop sign as a yield sign and a red light as a stop sign if and only if there is no cross traffic nor reason for the cyclist to yield to other vehicles or pedestrians at the intersection. They may also make left-hand turns at red lights only if onto a one-way street and only after stopping and yielding to other traffic and pedestrians.
• Cyclists can ride two abreast as long as they do not impede the normal flow of traffic. Drivers must yield to cyclists in order to give them an opportunity to go single file or move farther to the right, where they do not impede normal traffic flow. Traffic law and safety require slowing for or yielding to other vehicles, including cyclists, when necessary.

More Information

• Boulder County Driver and Cycling Laws and Guidelines brochure (PDF).
• Colorado Traffic Safety Laws Pertaining to Cycling.
• Rolling Coal/Excessive Emissions Hotline: Call 303-692-3211 to report a vehicle with excessive emissions.

NOTE: The information provided is for informational purposes and is not legal advice and does not comprehensively describe all rules or laws.

Boulder County wants to ensure that everyone has equal access to our programs, activities, and services. To request an Americans with Disability Act (ADA) accommodation, please email ada@bouldercounty.gov, or call 303-441-1386. If you need help in another language, please email cppfrontdesk@bouldercounty.gov or call 303-441-3930.