Motorcycle helmet and lane-splitting laws in Colorado

If you ride in Colorado, two rules cause more confusion after a crash than any others: who actually has to wear a helmet, and when you're allowed to move between cars. Colorado's answers are different from most states, and getting them wrong can hurt you both at the scene and later, when you file a claim. Colorado is also an at-fault state; it dropped no-fault insurance in 2003, so the driver who caused your crash, and that driver's insurer, pays for the harm.¹ Here is what the current statutes and the agencies that enforce them actually say.

Who has to wear a helmet

Colorado has a partial helmet law. Only operators and passengers under 18 are required to wear one, and that helmet has to meet the U.S. Department of Transportation standard set in Federal Motor Vehicle Safety Standard 218, 49 CFR 571.218.² If you're 18 or older, the choice is yours. No exception forces adult riders back into a helmet based on engine size, experience, or carrying a passenger. The under-18 rule covers both the operator and any minor passenger, and breaking it is a traffic offense. Even where the law leaves the call to you, a DOT-compliant helmet is the single biggest factor in surviving a head impact, so the legal minimum and the safe choice are not the same thing here.

Eye protection is the part riders miss. Colorado requires every rider, whatever their age, to wear glasses, goggles, or a transparent face shield unless the motorcycle is equipped with a windscreen.² That rule applies to the 40-year veteran the same as the 16-year-old, and it is a separate obligation from the helmet rule.

Lane splitting is illegal, lane filtering is not

People use "lane splitting" and "lane filtering" interchangeably, but Colorado treats them as two separate things, and only one is legal.

Lane splitting, riding the line to pass traffic that is still moving, remains illegal in Colorado.³ Lane filtering is the narrow, newer exception. Since August 7, 2024, a motorcyclist may pass between stopped vehicles under a specific set of conditions created by Senate Bill 24-079, which amended C.R.S. 42-4-1503.⁴⁵

The exact filtering rules

The Colorado Department of Transportation and the enacted statute lay out the conditions, and every one of them has to be true at the same moment. You may filter only when:

• the other vehicles are stopped, for example waiting at a red light, and not merely crawling in congestion;
• the lane is wide enough to pass safely;
• your motorcycle does not exceed 15 miles per hour while passing; and
• conditions let you operate the motorcycle prudently.³⁶

You have to pass on the left. You cannot use the right shoulder, pass to the right of a vehicle in the far right lane, or cross into oncoming traffic.⁶ The moment the stopped cars start moving again, you have to stop filtering and merge back into the flow.⁶

Notice what is not on that list: a posted speed limit. Some early write-ups claimed filtering is allowed only on roads posted at or below a set speed. The statute contains no roadway speed-limit condition. What matters is whether the traffic you're passing is fully stopped, not the number on the sign.⁶

This is a pilot, not a permanent rule. The filtering authorization repeals on September 1, 2027, and CDOT has to study crash data during that window and report to the legislature before then.⁴⁶ The three-year sunset exists so the state can measure whether filtering cuts down on rear-end crashes at lights, the safety rationale riders' groups pushed, before lawmakers decide whether to keep it. Unless they renew it, filtering becomes illegal again on that date, so the rule you rode under last summer may not be the rule next year.

What helmet non-use means for your claim

Here's the part that matters most if you've already been hurt. Because Colorado doesn't require adults to wear a helmet, a defense lawyer can't turn your bare head against you. In Dare v. Sobule, the Colorado Supreme Court held that a rider's failure to wear a helmet cannot be admitted to prove contributory negligence or to show the rider failed to mitigate damages.⁷ Colorado's civil jury instructions carry the same rule: if that evidence somehow reaches the jury, the injured rider is entitled to an instruction that not wearing a helmet is not negligence.⁸

In plain terms, the driver who turned left across your path is responsible for the crash they caused, and your recovery does not shrink because you rode without a helmet, which Colorado law let you do.

Eye protection is treated differently. Because Colorado does require it for every rider, riding with no glasses, goggles, or shield and no windscreen is an actual traffic violation, which gives a defendant more room to argue it contributed if wind or debris played any role in the crash.

Filtering is a different story too. If you were filtering outside the legal conditions, say you were doing 25 through stopped cars, or splitting lanes that were still moving, that violation can be treated as evidence of your own negligence. And that matters because of how Colorado divides fault.

How Colorado fault and deadlines affect the case

Colorado uses modified comparative negligence with a 50% bar. You can recover as long as you're found less than 50% at fault, but your award is reduced by your share, and at 50% or more you get nothing.⁹ An illegal filtering or splitting maneuver is exactly the kind of fact an insurer will lean on to push your percentage higher.

Impaired drivers cause a heavy share of motorcycle deaths, and Colorado gives injured riders an added tool there: exemplary, or punitive, damages for willful and wanton conduct such as drunk driving, available up to the amount of the compensatory award.¹⁰

Time is the other trap. Colorado gives you three years from the date of a motor-vehicle crash to sue for injuries or property damage, longer than the general two-year tort deadline, but it still runs out.¹¹ Miss it and the claim is gone no matter how serious the injury.

One more thing to check before you settle is your own coverage. Riders are hurt badly by drivers who carry little or no insurance, so uninsured and underinsured motorist coverage often does the heavy lifting on a bike claim. Colorado insurers have to include UM/UIM with every auto policy unless you rejected it in writing.¹²

If your motorcycle lost resale value even after a clean repair, that is a separate claim; see diminished value in Colorado. For the police report you'll need to document fault, see Colorado crash reports. And when fault or the filtering question is genuinely contested, that is when a lawyer earns their fee; you can find one through the legal directory.

This article is general information, not legal advice.

Sources

1. Colorado Division of Insurance, Auto Insurance. https://doi.colorado.gov/types-of-insurance/auto-insurance

2. Colorado Revised Statutes 42-4-1502, motorcycles and autocycles, protective helmet and eye protection. https://content.leg.colorado.gov/sites/default/files/images/olls/crs2024-title-42.pdf

3. Colorado Department of Transportation, Motorcycle Lane Filtering. https://www.codot.gov/safety/motorcycle/lanefiltering

4. Colorado General Assembly, Senate Bill 24-079, Motorcycle Lane Filtering and Passing. https://leg.colorado.gov/bills/sb24-079

5. Colorado Revised Statutes 42-4-1503, overtaking and passing by motorcycles (lane filtering). https://content.leg.colorado.gov/sites/default/files/images/olls/crs2024-title-42.pdf

6. Colorado Department of Transportation, New lane filtering law protects motorcyclists. https://www.codot.gov/safety/shift-into-safe-news/2024/june/new-lane-filtering-law-protects-motorcyclists

7. Dare v. Sobule, 674 P.2d 960 (Colo. 1984). https://law.justia.com/cases/colorado/supreme-court/1984/82sc162-0.html

8. Colorado Judicial Branch, Colorado Jury Instructions, Civil, Chapter 5. https://www.coloradojudicial.gov/sites/default/files/2025-02/Chapter%205.pdf

9. Colorado Revised Statutes 13-21-111, comparative negligence. https://content.leg.colorado.gov/sites/default/files/images/olls/crs2024-title-13.pdf

10. Colorado Revised Statutes 13-21-102, exemplary damages. https://content.leg.colorado.gov/sites/default/files/images/olls/crs2024-title-13.pdf

11. Colorado Revised Statutes 13-80-101(1)(n)(I), three-year limit for motor-vehicle tort claims. https://content.leg.colorado.gov/sites/default/files/images/olls/crs2024-title-13.pdf

12. Colorado Revised Statutes 10-4-609, uninsured and underinsured motorist coverage. https://content.leg.colorado.gov/sites/default/files/images/olls/crs2024-title-10.pdf