The California Air Resource Board (CARB) recently proposed a program which focuses on the reduction of emissions and pollutants by limiting idling of new heavy-duty diesel vehicles.

The new measure, which was widely discussed at CARB’s March 23 public workshop, requires 2008 and subsequent model year on-road heavy-duty diesel engines (with a gross vehicle weight rating > 14,000 lbs) to be equipped with a non-adjustable and tamper resistant electronic idle controls that will shut down the engine if it is left to idle for more than 5 minutes.

The requirements may include provisions that would allow the vehicle driver or operator to override the electronic idle limiting device as needed for safety or if the vehicle is stopped in traffic or to operate power take-off devices.

CARB says the newly proposed program is designed to limit idling of diesel-fueled commercial motor vehicles. The measure allows the use of other technologies which help provide heating and cooling for the cab, engine oil heating for easy start-ups in cold weather, and electric power. These devices may include on-board auxiliary devices, such as fuel-fired heaters and auxiliary power units (APU), power inverter/chargers for use with battery packs and grid supplied electricity.

According to CARB, the use of these proposed devices will result in “significant NOx reductions.” A formal rule is expected at some point in May.