ARLINGTON, Va. -- The American Transportation Research Institute has released an updated version of its online listing of state and local idling regulations.

The update details new idling limits in North Carolina, West Virginia and Detroit.

A new law in North Carolina limits idling to five minutes, with the exception of idling for air conditioning or heating sleeper berth compartments during federally mandated rest or sleep periods.

This exemption expires on May 1, 2011. Other exemptions include the idling of engines which meet the California low-NOx idling standard and when using an auxiliary power unit.

A 15-minute limit in West Virginia's exemption for sleeping or resting in a sleeper berth when temperatures are less than 40 degrees or greater than 75 degrees will expire on May 1, 2012. An exemption is also provided for trucks displaying a CARB-issued low-NOx idle label.

In Detroit, an exemption is provided for vehicles which remain motionless for more than two hours when the temperature is less than 25 degrees.