California air quality regulators have issued an order that will prohibit big-rig trucks with sleeping berths from idling their diesel engines while parked.
The order, adopted late Thursday by the California Air Resources Board, is believed to be the first in the nation to require big sleeper trucks to shut off their engines during layovers, according to the agency.
The decision will affect an estimated 180,000 big-rig trucks operating on California roads every day, most of them equipped with sleeper cabs, CARB spokesman Jerry Martin said. About 40,000 sleeper trucks are from outside California.
The air board estimates that while big rigs in California are idling, they emit 53 tons a day of nitrogen oxide, which contributes to the formation of smog, Martin said.
In 2004 California ordered operators of commercial trucks and buses to shut off their engines after idling for five minutes, but the rule did not cover trucks with sleeping berths unless they were within 100 feet of a home or school.
The new rule will go into effect for engines on 2008 model year trucks weighing more than 14,000 pounds. Trucks will have to be equipped with a system to automatically shut off the engine after five minutes.
Owners of pre-2008 sleeper trucks may have to install an auxiliary power supply or some other equipment to provide heat or air conditioning for the cab.
Operators idle their engines overnight at truck stops and rest areas to heat or cool the sleeping area and to operate electrical appliances and charge batteries.
The measure was opposed by trucking industry groups, which said there are no efficient auxiliary power supplies currently available for sleeper trucks and a no-idling rule could threaten the safety of drivers who need to rest.
Federal regulations require a driver must be off-duty for 10 hours after working a 14-hour shift.
In a separate decision, the air regulators directed state transit agencies to add filters to older diesel buses to trap pollutants.