A new regulation, developed by the Pennsylvania Department of Environmental Protection, would limit the amount of time a diesel truck can idle its engine to no more than five minutes in a 60-minute period.

The rule is aimed, primarily, at long-haul truckers, many of whom idle their vehicles during rest periods to provide heating, cooling and power to their bunks and cabs. Many delivery trucks, school buses, transit buses and motor coaches will also be affected.

The regulation must now be opened to public comment and be discussed in a public hearing before final consideration by the EQB. It then must be approved by the Independent Regulatory Review Commission, which reviews all proposed state regulations and, finally, the state attorney general.

Pennsylvania joins 14 other states, including Delaware, Maryland, New Jersey and New York in adopting anti-idling measures.

DEP estimates that 13,000 long-haul trucks idle in Pennsylvania each day. If each of these trucks used alternative means to provide drivers with power during rest periods, fuel use would be cut by more than 20 million gallons a year.

At diesel’s current statewide average cost of $3.19 per gallon, truckers are spending nearly $67 million each year on fuel to idle their vehicles during rest periods.

DEP also says the new regulation – once fully enacted in 2010 – will reduce annual emissions of NOx by about 1,610 tons, VOCs by about 45 tons, and particulate matter by about 30 tons.

Pennsylvania joins 14 other states, including Delaware, Maryland, New Jersey and New York in adopting anti-idling measures.