No — and what Colorado legalized is not quite what people describe
Lane splitting is illegal in Colorado and always has been. What changed in 2024 is narrower and stranger than the coverage suggests, and it comes with an expiry date.
Senate Bill 24-079 was approved by the Governor on 4 April 2024 and took effect on 7 August 2024. Its title is “Motorcycle Lane Filtering & Passing”, but read the enacted summary and the operative words are these: it authorizes the driver of a two-wheeled motorcycle “to overtake or pass another motor vehicle in the same lane“.
In the same lane. Not between lanes. That distinction matters, because the general statute is still on the books.
The rule that did not change
C.R.S. 42-4-1503 governs motorcycles on roadways laned for traffic, and subsection (3) reads: “A person shall not operate a motorcycle or autocycle between lanes of traffic or between adjacent lines or rows of vehicles.”
That prohibition remains. So the picture riders carry from California — threading the white line between two columns of cars — is not what Colorado authorized. Colorado authorized moving up within a lane past a stopped vehicle occupying it.
The rest of the section is worth knowing while you are here:
- Subsection (1) entitles all motorcycles to full use of a traffic lane and prohibits any motor vehicle from being driven so as to deprive a motorcycle of it — a protection for you, expressed as a duty on drivers.
- Subsection (4) caps side-by-side riding: not more than two abreast in a single lane. Two is therefore permitted, and subsection (1) explicitly does not apply to motorcycles riding two abreast.
- Subsection (5) exempts police officers in the performance of their duties from the same-lane and between-lanes prohibitions.
- Subsection (6) makes a violation a class A traffic infraction.
The four conditions in the enacted bill
Per the Colorado General Assembly’s summary of SB24-079 as enacted, a two-wheeled motorcycle may overtake or pass another motor vehicle in the same lane if all of the following hold:
| Condition | Wording |
|---|---|
| Traffic state | The traffic is stopped |
| Room | The road has lanes wide enough to pass safely |
| Speed | The motorcycle is moving at 15 miles per hour or less |
| Judgement | Conditions permit prudent operation of the motorcycle while overtaking or passing |
And three things the rider must not do while passing under the act: pass on the right shoulder; pass to the right of a vehicle in the farthest right-hand lane if the highway is not limited access; or pass in a lane of traffic moving in the opposite direction.
Where the state’s own explainer simplifies
This is worth flagging plainly, because a rider relying on the friendlier version could end up outside the statute.
The Colorado Department of Transportation’s public page on lane filtering lists five conditions, one of which is that “the motorcycle passes on the left of the vehicle in front”, and adds that when the stopped vehicles begin to move, the motorcyclist must re-enter the flow of traffic. It prohibits passing on the right shoulder and crossing the centre line into oncoming traffic.
The enacted bill’s restriction is worded differently. It does not say “pass on the left”. It says the rider must not pass to the right of a vehicle in the farthest right-hand lane if the highway is not limited access — a narrower and more conditional rule, which turns on which lane the vehicle is in and what kind of road you are on.
Both are quoted above so you can see the difference. CDOT’s summary is the safer of the two to ride by, since anything satisfying it also satisfies the statute. But if you want to know what the law actually says, it is the bill text, and the two are not identical.
The expiry date
The single most under-reported fact about Colorado’s law: it ends on its own.
“The authorization to overtake or pass is repealed, effective September 1, 2027.” Before then, the Colorado Department of Transportation will analyse safety data from the change and issue a report to the general assembly. CDOT’s public page puts the same thing as “this law will automatically expire in September 2027.”
Unless the legislature acts on that report, Colorado reverts to the position it held before August 2024 — the general prohibition, with no same-lane passing exception. This was a three-year pilot from the start, and any guide that describes Colorado as simply “a filtering state” is missing the clock on it.
What this means at the lights
Three practical readings, given the text rather than the headline.
The traffic must be stopped, fully. A queue creeping forward is not stopped, and there is no tolerance written into the bill. Montana is the only state that permits the maneuver against traffic still moving, at up to 10 mph.
Fifteen miles per hour is slow. Roughly a fast jog. It is the condition riders break most often without noticing, and it applies to your speed, not the difference between you and the traffic.
You are working inside a lane, not between two. Read literally, the authorization covers passing a stopped vehicle in the lane you are already in. Subsection (3)’s ban on riding between lanes was not repealed.
And one thing that is not affected by any of it: the helmet rule. Colorado requires one from riders and passengers aged 17 and younger, with no adult requirement — the national table is in motorcycle helmet laws by state, and the federal crash figures behind that choice in motorcycle accident statistics. Nor does filtering excuse riding without the endorsement, which in Colorado means the twelve-month permit for under-18s and a state that refuses civilian out-of-state MSF cards.
Elsewhere
Colorado was the fourth state to authorize a version of this, after Utah in 2019, Montana in 2021 and Arizona in 2022, with Minnesota following in 2025. All five sit side by side, with their different speed limits and conditions, in lane filtering. The position in every other state is in motorcycle lane splitting laws by state.
The two neighbours riders ask about most are covered in is lane splitting legal in Arizona, whose statute is worded quite differently, and is lane splitting legal in New Jersey for anyone heading east. Colorado’s own licensing rules, including the twelve-month permit for under-18s and the state’s refusal of out-of-state MSF cards, are in motorcycle license Colorado. Helmet rules by state are in motorcycle helmet laws by state.
Frequently asked questions
Is lane splitting legal in Colorado?
No. C.R.S. 42-4-1503(3) prohibits operating a motorcycle between lanes of traffic or between adjacent lines or rows of vehicles, and that has not been repealed. What SB24-079 authorized in 2024 is passing another vehicle in the same lane, under conditions.
What are the conditions for lane filtering in Colorado?
Traffic must be stopped, the road must have lanes wide enough to pass safely, the motorcycle must be moving at 15 mph or less, and conditions must permit prudent operation. The rider must not pass on the right shoulder, to the right of a vehicle in the farthest right-hand lane on a highway that is not limited access, or in a lane of oncoming traffic.
When does Colorado’s lane filtering law expire?
1 September 2027. The authorization to overtake or pass is repealed on that date, and before then the Colorado Department of Transportation must analyse safety data and report to the general assembly.
How fast can you filter in Colorado?
15 miles per hour or less. That is the motorcycle’s own speed, not a differential against the traffic, and the traffic must be stopped in any case.
Can two motorcycles ride side by side in Colorado?
Yes. C.R.S. 42-4-1503(4) prohibits operating more than two abreast in a single lane, so two is permitted, and the full-lane entitlement in subsection (1) expressly does not apply to motorcycles riding two abreast.
What is the penalty for illegal lane splitting in Colorado?
A violation of section 42-4-1503 is a class A traffic infraction under subsection (6) of that section.