Green Vehicle Laws and Regulations in Washington DC

Eco-friendly Washington D.C. drivers can learn more about state laws that pertain to green vehicles. Whether you drive a hybrid, electric car, or any other alternative fuel vehicle, be aware of state-specific regulations for fuel-efficient vehicles.

Although D.C.'s general traffic laws rarely change, regulations specific to protecting the planet are ever-evolving. Two additional resources worth keeping pace with include your local Department of Motor Vehicles (DMV) branch and the Alternative Fuels Data Center. For more on how to save money and time as a green-minded driver, consult our District of Columbia Green Driver Incentives page.

Washington D.C. Green Vehicle Registration and Emissions

The D.C. Department of Motor Vehicles exempts zero emissions vehicles (ZEVs) from the emission inspection (otherwise required during the vehicle registration process). For more on emissions test exemptions in Washington D.C., consult our Green Driver Incentives and Smog and Emissions Check pages.

As the owner of an electric vehicle (hybrid) or clean-fuel vehicle you might also be eligible for a reduced vehicle registration fee. Refer to the section on D.C. tax breaks also covered on our Green Driver Incentives page.

Idle Reduction Requirement for all D.C. Motorists

According to, idling can burn through a quarter to a half-gallon of gas per hour. Not only is this bad for your pocketbook and the environment, it’s also illegal in the District of Columbia.

If your vehicle is powered by diesel fuel or gasoline, you may not leave it idling (for air conditioning purposes) for more than three consecutive minutes while parked, stopped, or standing. Exceptions to the rule include:

  • When operating power takeoff equipment (such as dumping, cement mixers, refrigeration systems, content delivery, winches, or shredders).
  • When operating private passenger vehicles.
  • When idling the engine for five minutes to run heating equipment when the temperature is at or below 32 degrees Fahrenheit.

The rule also applies to public vehicles for hire (including buses that seat 12 or more people. For specifics on illegal engine idling, refer to the District of Columbia Municipal Regulations (Title 20, Chapter 9).

Requirements for Acquiring Alternative Fuel Fleet Vehicles

Operating a fleet—in what the Clean Air Act defines as an ozone nonattainment area—comes with a couple of requirements. If your fleet expands to 10 or more vehicles, a certain percentage of your newly purchased vehicles must use clean fuel. Washington D.C. uses gross vehicle weight rating (GVWR) to determine that number:

  • GVWR of 8,500 pounds or less—70% of new purchases must be clean fuel vehicles.
  • GVWR between 8,500 and 26,000 pounds—50% of new purchases must be clean fuel vehicles.
For specifics, refer to District of Columbia Code 50-702 through 50-703.

What is a Clean Fuel?

In meeting the AFV acquisition requirement mentioned above, D.C. considers a clean fuel as any fuel or other power source that complies with certain standards applicable when operating a clean fuel vehicle. These power source and fuel types include:

  • Electricity.
  • Diesel.
  • Ethanol (including E85).
  • Hydrogen.
  • Liquefied petroleum gas (propane).
  • Natural gas.
  • Reformulated gasoline.
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