Iowa Truck Idling Law
Iowa has no statewide idling time limit. Beyond the state idle-reduction weight allowance (Iowa Code 321.463 — up to 550 pounds, framed around natural-gas APU vehicles), local restrictions exist: Des Moines bars a heavy vehicle from idling more than 20 minutes within 150 feet of a residential zone (Municipal Code 42-259).
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
Iowa's 550-pound weight allowance (Iowa Code 321.463) applies specifically to natural-gas vehicles with an APU/idle-reduction unit (written certification required); diesel trucks rely on the federal 550-pound APU allowance (23 U.S.C. 127) on Interstate highways.
City and county ordinances
- Des Moines: a heavy vehicle (GVWR 10,000 lbs or more) may not run its engine or auxiliary engine more than 20 minutes while standing within 150 feet of property zoned and used for residential purposes; delivery/pickup vehicles are exempt only where the engine must run to load or unload (Municipal Code 42-259).
Iowa Idling Law FAQ
Is there a truck idling law in Iowa?
How long can a truck idle in Iowa?
What is the fine for idling in Iowa?
Does an APU count as idling in Iowa?
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 Traffic laws change and this can be out of date, so always confirm the current statute and obey posted signs before you rely on it.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=IA. See our Terms & Disclaimer.
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