U.S. Department of Energy - Energy Efficiency and Renewable Energy
Alternative Fuels and Advanced Vehicles Data Center
Maryland Idle Reduction Laws and Incentives
State Laws and Regulations
Idle Reduction Requirement
A motor vehicle engine may not operate for more than five consecutive minutes when the vehicle is not in motion, with the following exceptions: 1) traffic conditions or mechanical difficulties; 2) operation of heating, cooling or auxiliary equipment installed on the vehicle; 3) bring vehicle to manufacturer's recommended operating temperature; or 4) when it is necessary to accomplish the intended use of the vehicle. Violators may be subject to a fine of up to $500. (Reference Maryland Statutes, Transportation Code 22-402 and 27-101)