Wyoming Truck Idling Law
Wyoming has no statewide idling time limit. In 2023 the state repealed (HB 239) the old requirement to shut off the engine and take the key when leaving a vehicle unattended, so there is now no state law forcing you to kill the engine — W.S. 31-5-509 only requires setting the brake and curbing the wheels on a grade. Cities can still restrict idling: Rawlins, on the I-80 corridor, caps parked idling at 20 minutes.
Some figures on this page are flagged medium confidence. The limit and source are solid, but a specific fine or local detail should be confirmed with the state agency before you rely on it.
When you can keep idling
This state has no statewide idling limit, so there are no statutory exemptions to list. Local ordinances, where they exist, carry their own.
APUs and idle-reduction gear
No statewide rule.
City and county ordinances
- Rawlins (I-80): idling while parked limited to 20 minutes, attended or unattended (Municipal Code 10.03.070); misdemeanor citation and possible tow; APU-equipped commercial vehicles and emergency vehicles exempt, and the rule is suspended when area highways are closed.
Wyoming Idling Law FAQ
Is there a truck idling law in Wyoming?
How long can a truck idle in Wyoming?
What is the fine for idling in Wyoming?
Does an APU count as idling in Wyoming?
Reference information for planning, not legal advice. Traffic laws change and this can be out of date, so always confirm the current statute and obey posted signs before you rely on it. Last reviewed July 2026. Source: https://afdc.energy.gov/fuels/laws/IR?state=WY. See our Terms & Disclaimer.
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