BOSTON – Officials for the state of Massachusetts are considering allowing single travelers in hybrid cars to use the car pool lane to encourage the use of environmentally-friendly cars, according to the Associated Press.

The policy would apply to the six-mile zipper lane on the Southeast Expressway and the two-mile high-occupancy lane on Interstate 93 southbound from Somerville to Leonard P. Zakim Bunker Hill Bridge, as reported by the Boston Globe.

A national policy would have to be instituted before the state would open up car pool lanes to hybrids since there has been some confusion in some other states that have tried the idea, according to state officials. Virginia has been allowing hybrid vehicles in car pool lanes without federal approval.

"No decision has been made, but the idea of providing an incentive for the purchase of clean vehicles is a very attractive one, especially as more choices become available to consumers," said Philip Hailer, a spokesman for the Office of Commonwealth Development, the department that oversees transportation and environmental affairs.