PHOENIX --– Arizona Gov. Janet Napolitano announced that several types of fuel-efficient hybrid cars will now be allowed to use the carpool lanes on the state highways, even when the driver has no passengers. Typically, use of those lanes is restricted to vehicles carrying multiple passengers. Under the new Energy Efficient Pilot Program, however, qualified hybrids -– even with a lone driver -– will also be able to occupy the carpool lanes. The pilot is part of the governor's Clean Air Initiative and begins immediately. "We’re using a variety of strategies to begin to clear the air in Arizona," said Napolitano. "Drivers who make the commitment to clean air and energy efficiency will get an easier commute. That seems like a good trade to me." Vehicles that are able to achieve a 45 percent increase in combined city/highway fuel efficiency are eligible to participate in the program. Currently, three types of vehicles qualify: the Honda Insight, the Honda Civic Hybrid and the Toyota Prius. Owners of those cars will need to apply for the program through the Motor Vehicle Division of the Arizona Department of Transportation. Once admitted to the pilot, owners will receive a special license plate, as well as a special sticker indicating the car is a part of the pilot. The program is limited to 10,000 vehicles on a first-come, first served basis. There are currently approximately 9,000 of these types of cars registered in Arizona. The pilot program will remain in place while the EPA continues its long-term rule-making process for the use of high-occupancy vehicle lanes. The change also affects drivers of bi-fuel vehicles. Under the terms of the pilot, and according to federal law, bi-fuel vehicles operating with only the driver on-board will no longer be allowed to use the carpool lanes. Any vehicle carrying two or more people will continue to be allowed to use the special lanes. Within 90 days, the state Motor Vehicle Division (MVD) will issue bi-fuel owners a new bi-fuel plate; owners will be expected to destroy their current alternative fuel plate. This change does not impact bi-fuel owners' reduced vehicle license taxes.