PHOENIX — Hold on to your plug-in hybrid for as long as you can if you want to drive alone in the carpool lane.

Effective March 2, Arizona’s energy efficient plate program is over.

The program allows drivers of eligible plug-in hybrid vehicles to travel in the HOV lane without passengers during restricted times during rush hour. But not for much longer.

“Holders of energy efficient plates may continue to use those on their vehicle for as long as they have that vehicle,” Doug Nick, spokesman for the Arizona Department of Transportation’s Motor Vehicle Division, said Friday. “So even though you go past March, if it’s still the same vehicle you can still use the HOV lane.”

However, if the vehicle is sold, traded or has its title transferred, the energy efficient plate is no longer valid.

Until March 2, current plate holders may transfer the plate to a new qualifying energy efficient vehicle. As of that date, it will no longer be permitted.

“So eventually it’s going to end more or less through attrition, but those cars that are currently out there will be able to use those lanes for the life of their vehicle,” Nick said.

Energy efficient plates will no longer be issued to new participants.

The program is being discontinued to comply with federal regulations regarding HOV lane usage.

The change does not impact HOV privileges for fully electric cars and other vehicles with Arizona alternative fuel plates.

Follow @Ali_Vetnar