Heavy-Duty Vehicle Idling Emission Reduction Program

This page last reviewed October 24, 2013

NOTICE: The grace period for idling sleeper berth vehicles is now over. Find out more about this from our news release.


As a follow up to the in-use idling airborne toxic control measure (ATCM) adopted on July 22, 2004, the Air Resources Board, on October 20, 2005, approved a regulatory measure to further reduce emissions of toxics and criteria pollutants by limiting idling of new and in-use sleeper berth equipped diesel trucks. The regulation consists of new engine and in-use truck requirements and emission performance requirements for technologies used as alternatives to idling the truck's main engine.

The new engine requirements require 2008 and newer model year heavy-duty diesel engines to be equipped with a non-programmable engine shutdown system that automatically shuts down the engine after five minutes of idling or optionally meet a stringent oxides of nitrogen idling emission standard. The in-use truck requirements require operators of both in-state and out-of-state registered sleeper berth equipped trucks to manually shut down their engine when idling more than five minutes at any location within California beginning in 2008.

Emission producing alternative technologies such as diesel-fueled auxiliary power systems (APS) and fuel-fired heaters are also required to meet emission performance requirements that ensure emissions are not exceeding the emissions of a truck engine operating at idle. Specifically, the regulation requires diesel APSs installed on trucks with 2007 and newer engines to control particulate matter (PM) emissions by either routing the APS exhaust through the PM trap of the truck engine or by retrofitting the diesel APS with a verified level 3 PM control device that reduces PM emissions by at least 85 percent. Fuel fired heaters installed on trucks with 2007 and newer engines are also required to meet the Ultra Low Emission Vehicle requirements specified in the Low Emission Vehicle regulations. These requirements are effective beginning in 2008.

For trucks equipped with 2006 and older engines, any California or federally certified diesel-fueled APS or fuel-fired heater may be used.

What's New

  • Regulatory Documents for Proposed Amendments to the ATCM to Limit Diesel-Fueled Commercial Motor Vehicles Idling (Posted October 24, 2013)
    The Air Resources Board will conduct a public hearing on December 12, 2013, in Sacramento, to discuss proposed amendments to the ATCM to Limit Diesel-Fueled Commercial Motor Vehicle Idling (title 13, CCR, section 2485). The public hearing notice and staff report have been posted on the proposed regulations webpage. The amended regulatory language can be found in Appendix 1-D.

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