WASHINGTON, D.C. – The Environmental Protection Agency (EPA) proposed new criteria May 17 for certifying vehicles as clean and energy efficient — standards for states that let hybrid drivers travel without passengers in the special lanes to avoid rush-hour traffic, according to the Web site www.chron.com.

For the driver of a hybrid to qualify for HOV lanes during peak time, hybrid vehicles would need to achieve 25 percent higher combined fuel efficiency for city and highway driving compared with similar gasoline-fueled vehicles. The new criterion was developed for the Transportation Department, which administers HOV programs.

States typically restrict high occupancy vehicle, or HOV, lanes to vehicles with two or more people during designated hours. However, The federal highway bill signed in 2005 allowed an exemption for fuel-efficient vehicles carrying only the driver. States that allow solo hybrid drivers in car pool lanes include Arizona, California, Florida, Utah, and Virginia, according to the Web site www.chron.com. Lawmakers in Georgia and Colorado have approved similar plans, and the vehicles can also be used in HOV lanes on a highway on New York’s Long Island.

The EPA measure allows states to choose stricter rules. California, which has an estimated 140,000 hybrid registrations, requires the vehicles to get 45 mpg to use HOV lanes.

Hybrids also could qualify as energy-efficient by achieving 50 percent or better in-city fuel economy. Dedicated alternative-fuel vehicles could qualify to use the lanes as well. To be considered low emission, the EPA said the vehicles would need to meet federal and California emissions standards.