SACRAMENTO– In an effort to further reduce pollution from truck engine idling, the Air Resources Board (ARB) has passed a regulation adding heavy-duty trucks with sleeper cabs to the current prohibition on diesel engines idling for more than five minutes. The regulation applies to current and future trucks and will go into effect in 2008.

"This new rule will go a long way towards protecting the health of people who are typically exposed to truck emissions for long periods of time," said Barbara Riordan, Acting ARB Chair. "Idling emissions can be especially heavy at truck stops and also at warehouses, distribution centers and port terminals where loading and unloading of freight often requires drivers to wait, sometimes for hours. Fortunately several new technologies have been developed that provide for truck cabin cooling and heating when the truck's main engine shut off. These technologies reduce harmful emissions and reduce fuel use as well."

The ARB's new rule prohibiting prolonged idling will help to reduce public exposure and improve air quality at these heavily traveled locations. Nearby communities will also benefit from this action. The rule is a follow-up to earlier regulations that limit idling but excluded diesel trucks with "sleeper berths" which frequently depend on idling for cabin climate control and to run appliances.

There are two parts to the new rule. The first component regulates new 2008 and subsequent model year heavy-duty diesel engines, requiring them to be equipped with a non-programmable engine shutdown system that automatically shuts down the engine after five minutes of continuous idling.

The second component regulates in-use sleeper berth ("comfort cab") equipped trucks, including those registered out-of-state, requiring operators to shut off their engines before the five minute idling time is reached. The rule provides for the use of alternative technologies to provide power for "cab comfort" (e.g., heating, cooling, etc.) and on-board accessories that would otherwise have required continuous idling of the vehicle's main engine. These technologies have zero or very low pollution emissions.

According to ARB estimates, about 180,000 big-rig trucks operate on California roads each day emitting about 53 tons per day (tpd) of smog-forming nitrogen oxides (NOx) and 0.73 tpd of particulate matter (PM). About one quarter of those trucks are registered outside of California with 90 percent of those vehicles equipped with sleeper cabs. In addition to benefiting air quality, the new rule is expected to help reduce fuel consumption and engine maintenance costs for trucks that are in compliance.