Diesel Regulations

Code of Maryland Regulations (COMAR)

Maryland Law

  • Maryland Law Related to the DVECP (Transportation Article Sections 23-401 to 23-404)
  • Engine Idling
    A motor vehicle may not be allowed to idle for more than five consecutive minutes when the vehicle is not in motion, with the following exceptions: the vehicle is stopped due to traffic conditions or mechanical difficulties; the engine is operating heating and cooling or auxiliary equipment; to bring the engine to the manufacturer’s recommended operating temperature; or to accomplish the intended use of the vehicle.
  • Unattended Motor Vehicle
    A person driving or otherwise in charge of a motor vehicle may not leave it unattended until the engine is stopped, the ignition locked, the key removed, and the brake effectively set.

EPA Rules

  • 2007 Heavy Duty Highway Diesel Rule
    Beginning with the 2007 model year, harmful pollution from heavy-duty highway vehicles will be reduced by more than 90 percent. The sulfur concentration in highway diesel fuel must be no higher than 15 parts per million (ULSD) to enable the use of advanced pollution controls.
  • Clean Air Non-Road Diesel Engine & Fuel Rule
    Non-road engine and fuel controls are integrated as a system to gain the greatest emission reductions; new non-road engines will have advanced emission-control technologies similar to those already used for highway trucks and buses. This rule requires non-road diesel fuel to have a sulfur concentration no higher than 500 parts per million in 2007, and no more than 15 parts per million (ULSD) by 2010.
  • Direct Final Rule and Amendments to the Highway and Non-Road Diesel Rules (July 2005, November 2005, and April 2006)
    EPA amended the Highway Diesel and Non-Road Diesel rules to provide a temporary increase in the sulfur testing tolerance and to allow the use of biodiesel to ensure compliance with the diesel fuel regulations.
  • Clean Diesel Program for Locomotives and Marine Engines
    Information about EPA’s plan to propose more stringent emission standards and other provisions for new and existing locomotives and new marine diesel engines.

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