You’d think that allowing hybrid cars to use the high occupancy vehicle (HOV) or carpool lanes on hundreds of America’s highways would be an easy way to encourage car buyers in the United States to make the switch to fuel-efficient vehicles like the Toyota Prius and Honda Insight. A surprising number of states, however, still ban hybrids from these fast-moving, priority lanes. Even states that once allowed solo-hybrids in the fast lanes have ceased their programs.

States That Allow Hybrids in HOV Lanes

Several states have tried allowing hybrids in their HOV lanes in an effort to clear the air in major cities. California issued 85,000 permits in 2010 before closing the program to new applicants later that year. Tennessee, Virginia, Florida, and Colorado continue to allow hybrid owners to drive solo in the carpool lanes, and New York and New Jersey allow hybrids to travel in the HOV lanes on certain highways at certain times. Much to the dismay of Arizona Nissan dealers (the providers of the all-electric Leaf) and other Southwestern hybrid sellers, Arizona halted its program to allow solo hybrids in the HOV lanes in 2008, after issuing 10,000 permits. Utah has also ceased its hybrid program.

Arguments Against Single-Occupant Hybrids in HOV Lanes

Those opposed to legislation that would allow single-occupancy hybrid vehicles in HOV lanes maintain that the name (high occupancy vehicles) says it all. Others argue that some hybrid cars like the Nissan Leaf, which recharges its batteries using electricity, aren’t as fuel efficient as they may initially sound. This is somewhat true in states where most electricity is still generated by coal. According to CNN Money, in states like Indiana where 90 percent of the electricity is created using coal, a hybrid car that uses gasoline to recharge its batteries like a Toyota Prius may be a more environmentally-friendly choice.

Another argument against allowing hybrids in the HOV lanes is that the increasing the number of vehicles in these lanes causes the flow of traffic to slow down and therefore increases the carbon dioxide emissions in the atmosphere from traditional, gasoline-powered cars driving in the same lanes.

The Future of Hybrid Cars in HOV Lanes

The case for allowing single-occupant hybrid cars in HOV lanes is still a controversial one. Though a few states are considering legislation for new programs, many of the existing programs, such as those in Maryland and Virginia, are set to expire in the next few years. Whether these programs are renewed is anything but a sure bet.

As electric grids continue to evolve and hybrid cars continue to be more energy efficient, allowing these cars to drive with single occupants in HOV lanes just might be the incentive buyers need to make the switch to a hybrid car. But whether state legislators and the court of public opinion see the advantage has yet to be seen.