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U.S. Department of Energy Energy Efficiency and Renewable Energy

Fact #627: June 14, 2010
Idle Reduction for Heavy Trucks

In order to encourage the use of idling reduction devices in large trucks, the Energy Policy Act of 2005 allowed for a 400-pound weight exemption for the additional weight of idling reduction technology. States were given the discretion of adopting this exemption without being subjected to penalty.

Since then, most States have passed laws which allow trucks to exceed the maximum gross vehicle weight limit by an additional 400 lbs (white States) Other States have a 400 lb weight allowance which is granted by enforcement personnel (light blue States). Four States have legislation pending at this time (green States) and another four States have not adopted the weight exemption.

States Adopting 400-Pound Weight Exemption for Idling Reduction Devices, 2010
Map of the United States showing the states adopting 400-pound weight exemption for idling reduction devices in 2010. The map also shows the states where allowance is granted by enforcement rather than by state law, the states were legislation is pending, and the states with no exemption. For more detailed information, see supporting information below.

An additional incentive for equipping large trucks with idle reduction technologies was in the Energy Improvement and Extension Act of 2008. The Act excludes certain idling reduction devices and advanced insulation from Federal excise taxes. Products which are eligible for the tax exemption include:

  • fuel operated heaters,
  • battery air conditioning/heating systems,
  • auxiliary power units/generator sets,
  • thermal storage systems, and
  • shore connection systems

Supporting Information

State Recognition of the 400-Pound Auxiliary Power Unit Exemption to the Gross Vehicle Weight Limit
States Allowing Exemption States where Allowance is Granted by Enforcement States where Legislation is Pending for Exemption States That Have Not Adopted the Exemption
Alaska Arkansas Alabama Georgia
Arizona Idaho California Hawaii
Colorado Illinois Florida Kentucky
Connecticut Iowa Massachusetts North Carolina
Delaware Louisiana   Rhode Island
Indiana* Maryland   Tennessee
Kansas Michigan    
Maine Mississippi    
Minnesota Montana    
Missouri Nevada    
Nebraska New Hampshire    
New Mexico New Jersey    
North Dakota New York    
Oklahoma Ohio    
Oregon South Dakota    
Pennsylvania Texas    
South Carolina Utah    
Virginia Vermont    
Washington      
West Virginia**      
Wisconsin      
Wyoming      

* Effective July 1, 2010
** Effective June 11, 2010
Sources: U.S. Department of Energy, Energy Efficiency & Renewable Energy, National Idling Reduction News, April 2010.
U.S. Environmental Protection Agency, SmartWay Transport Partnership.

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