California Truck Idling Law
California has the strictest rule in the west. No diesel truck over 10,000 pounds may idle its main engine more than 5 minutes anywhere (13 CCR 2485, CARB), and 2008-and-newer engines must shut down automatically at 5 minutes. The sleeper-berth break only covers pre-2008 engines. Fines start at $300, and the DMV can block your registration until you clear them.
When you can keep idling
- Traffic or queuing, kept at least 100 feet from homes and schools
- Repairs, service, or DPF regeneration
- PTO and reefer work
- A safety or health emergency
- Sleeper-berth rest, only on pre-2008 engines and 100+ feet from homes and schools
APUs and idle-reduction gear
A diesel APU cannot run over 5 minutes within 100 feet of homes or schools, and 2007-and-newer trucks need PM controls. Idle-reduction gear earns a 400-pound weight allowance.
City and county ordinances
- Regional air districts (South Coast, San Joaquin Valley, Bay Area) mirror the 5-minute rule.
California Idling Law FAQ
Is there a truck idling law in California?
How long can a truck idle in California?
What is the fine for idling in California?
Does an APU count as idling in California?
This page is reference information for planning, not legal advice. Idling rules change and many are local. Confirm the current rule with the state environmental or transportation agency before you rely on it. Source: https://afdc.energy.gov/fuels/laws/IR?state=CA.
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