Truck Idling Law for California

Updated: March 3, 2021

Pursuant to state regulation, operators of diesel-fueled trucks, with a gross vehicle weight rating greater than 10,000 pounds, shall not idle for more than 5 minutes when stopped within California’s borders. Currently, there is an exemption for sleeper berth trucks, which allows them to idle during periods of sleep and rest. However, starting JANUARY 1, 2008, this will change; all sleeper berth trucks, regardless of model year, will also be required to shutdown their engines after 5 minutes.

As the 2008 regulatory deadline draws near, it will be necessary for many sleeper truck operators to select idle reduction equipment suitable for their cab comfort needs. To assist operators who may not be familiar with idle reduction technologies, ARB has developed this webpage to provide general information regarding various technologies that are currently available.

All idle reduction alternatives presented here require some amount of out-of-pocket expense. However, it is expected that operators will recover their costs over time through fuel and maintenance savings. ARB estimates that cost recovery times will range between 8 months and 3 years, but actual recovery times will depend solely on the equipment selected and the amount of time spent at idle.

In the spirit of air pollution prevention, ARB encourages the use of zero- and low-emissions technologies such as battery-powered systems, thermal energy storage systems, and truck-stop electrification systems. Selecting certain zero-emissions technologies may qualify you for financial incentives through California’s Carl Moyer Program. Please visit the program webpage or contact your local air district for details.