Montana Move Over Law: How Much to Slow Down and When to Change Lanes
How much do I have to slow down for a stopped police car or highway worker vehicle with lights on in Montana?
Under Montana law, when you pass a stopped police, emergency or highway worker vehicle with its lights on, slow to the temporary posted limit. If none is posted, slow to 20 mph below the posted limit on the interstate, or 30 mph below on a state highway or county road, if you can move lanes. If you cannot, or on any other road, slow to half the posted limit.
Where the Montana move over facts come from
The speeds and lane rules come from Montana Code Annotated 61-8-388. The work zone rules come from section 61-8-314. The advice on moving emergency vehicles, roundabouts, flaggers and work zone charges comes from the Montana Driver Manual of the Motor Vehicle Division (MVD), May 2026 file. This guide is current as of 2026. Confirm the rules with the Montana Motor Vehicle Division (mvdmt.gov) before you drive.
Which vehicles does the Montana move over law cover?
Section 61-8-388 covers two kinds of stopped vehicle. The first is a stationary law enforcement vehicle or authorized emergency vehicle that uses its siren or emergency lights. The second is a stationary highway worker vehicle that uses its emergency lights. The rule applies to the driver of each moving vehicle that comes up to one of them. A moving emergency vehicle has a different rule, shown further down this page.
How fast can you go past a stopped vehicle with lights on?
| Road | If you can move lanes | If you cannot move lanes |
|---|---|---|
| Temporary speed limit posted | Slow to the temporary limit | Slow to the temporary limit |
| Interstate, no temporary limit | 20 mph below the posted limit | Half the posted limit |
| State highway or county road, no temporary limit | 30 mph below the posted limit | Half the posted limit |
| Any other road, no temporary limit | Half the posted limit | Half the posted limit |
Worked example: an 80 mph interstate and a 70 mph highway
These examples use a posted limit and the math of the law. On an interstate posted at 80 mph, 80 − 20 = 60 mph if you can move lanes. If heavy traffic keeps you in your lane, 80 ÷ 2 = 40 mph. On a state highway posted at 70 mph, 70 − 30 = 40 mph with a lane change, or 70 ÷ 2 = 35 mph without one. On another road posted at 40 mph, 40 ÷ 2 = 20 mph. Slow down with care, as the law requires. Test yourself with our free question on passing a patrol car when you cannot change lanes.
What to do when you see lights ahead
- 1Watch for flaggers and sign boards
Follow the instructions of a flagger or of a temporary sign board. The lane rules in step 3 apply only when neither is in place yet.
- 2Slow to the right speed
Use the temporary posted limit if there is one. If not, use the speed in the table above for your road and your lane options.
- 3Choose your lane
On a multi-lane highway, move to a lane that is not next to the lane of the stopped vehicle. The other option is to move over as far as safely possible.
Which lane and speed fit your road?
What happens in a Montana work zone?
A work zone is an area on a public highway, or next to it, where construction, repair, maintenance or survey work is done. Signs mark its boundaries and show its speed limit. Flaggers in orange use red flags or stop and slow paddles to guide traffic, and you must obey them. A traffic violation in a work zone is a misdemeanor. If a highway worker was in the zone at the time, within 1,000 feet of the violation, the fine is at least double the usual penalty. See the usual fines in our guide to Montana speed limits and fines. Try our question on a flagger with a STOP paddle at a green light.
What if the emergency vehicle is moving?
How to study the move over rules for the written test
- Read the emergency vehicle, work zone and roundabout parts of the Montana Driver Manual.
- Learn the three speed rules: the temporary limit, 20 or 30 mph below with a lane change, and half the limit without one.
- Remember that flagger and sign board instructions come before the lane rules.
- Try our free question on a fire engine behind you in an intersection.
- Our free practice questions are in English only. They help you practice and are not the official test.
Key takeaways
- The Montana move over law covers a stopped police or emergency vehicle with a siren or emergency lights, and a stopped highway worker vehicle with emergency lights.
- Slow to the temporary posted limit. If none is posted and you can move lanes, go 20 mph below on the interstate or 30 mph below on a state highway or county road.
- If you cannot move lanes, or you are on any other road, slow to half the posted limit.
- For a moving emergency vehicle, pull to the right and stop until it passes, but do not stop inside a roundabout.
- Next step: practice on the free Montana Class D practice test.
Montana move over law: common questions
Do I have to change lanes for a police car with lights on in Montana?
Not always. When no flagger or temporary sign board is in place, you have two options: on a multi-lane highway, move to a lane that is not next to the stopped car, or move over as far as you safely can. You must slow down in both cases. When traffic stops a lane change, your speed is half the posted limit.
Why does the Montana Driver Manual say 20 mph below on 50 mph roads?
The May 2026 manual file still prints an older rule: on roads posted 50 mph or more, drivers in the lane next to a stopped emergency or police vehicle slow to at least 20 mph below the limit. Section 61-8-388, from 2023, sets the current speeds: 20 or 30 mph below with a lane change, and half the limit without one. Follow the law.
Do I have to pull over for an ambulance coming toward me in Montana?
Yes. Pull over to the right edge of the road, or as near to the right as possible, when you see or hear an emergency vehicle with its siren and lights that comes from any direction. Then stop and stay stopped until it has passed. If you are in an intersection, drive through it before you pull over.
Can I be charged for driving unsafely near highway workers in Montana?
Yes. The Montana Driver Manual says you can be charged with Reckless Endangerment of a Highway Worker if you knowingly or negligently drive in a highway construction zone in a way that puts people or property in danger. The same applies if you purposely remove, ignore or hit a traffic control device. It is a misdemeanor with the same penalty as reckless driving.
Practise for your Montana Class D Knowledge test
5 free practice tests with 100 questions, answers and explanations.
Start free Practice Test 1Share or ask AI about this article
Continue the conversation or send this guide to someone who needs it.
Related guides
How to Get a Class 7 Learner's Licence in Alberta (2026 Steps)
You can apply for an Alberta Class 7 learner's licence at 14. See the four steps, the knowledge test fee, the temporary licence and what you may drive.
Florida Learner's License at 15: Requirements, Hours and Rules
How to get a Florida learner's license at 15: the tests, the course, parental consent, who must ride with you, when you can drive and what comes next.
Can International Students Drive in Michigan? License Rules
Yes, if you are temporarily in the U.S., you may drive on your home license, with a translation or IDP if it is not in English. See the F-1 and J-1 documents.