Hybrid Perks May Become Problems

According to statistics maintained by the Environmental Protection Agency, the cleanest and most popular hybrids, the Toyota Prius and Honda Civic, emit half as many smog-causing pollutants as a standard Honda Accord, Ford Explorer and other popular models.

In most cases, that clearly favors hybrids. But in carpool lanes, where two or three passengers are normally required, the benefits are negated. A car such as the Explorer with three people in it, for instance, pollutes less than three hybrids with solo travelers.

Still, the Prius, Civic and some other hybrids use less oil and emit far fewer greenhouse gases than virtually all gas-only models.

In 2000, Virginia lawmakers came up with the carpool perk as a way to encourage sales in the nascent hybrid market. The state's measure countered federal law but was allowed to remain while Congress resolved its position.

The extension moving through the General Assembly could come with new limits. The one-year extension approved by the House yesterday says hybrids bought after July 1, 2006, would not be able to use the HOV lanes on I-95/395.

When the hybrid exemption was instituted, 32 cars in all of Virginia had "clean fuel" tags -- a designation necessary for solo commuters to use HOV lanes. Six years later, more than 8,500 hybrid vehicles are in Northern Virginia, about three-quarters of the state's total of 11,600, according to the Department of Motor Vehicles.

"Virginia is now the second-largest market in the country for hybrids, after California," Shosteck said, "and [the HOV exemption] is one of the biggest reasons."

Staff writer Chris L. Jenkins contributed to this report.