The U.S. Department of Transportation today rejected Pennsylvania's bid to impose tolls on vehicles traveling on the portion of Interstate 80 connecting the state from east to west, effectively killing the state's revenue-raising plan.

The DOT action marks the third time federal regulators have rejected the proposal, which would have made Pennsylvania the first state to convert an entire existing interstate highway to a toll road. The prior two attempts had come under previous presidential administrations. The commonwealth's lawmakers gave it a third try in hopes that a new administration might rule differently.

After today's decision, Pennsylvania Gov. Ed Rendell said the state's tolling attempts were "over," according to NATSO, a trade group representing truck stops and travel plazas. NATSO opposed the tolling measure, arguing that motor fuel taxes remain the most equitable source of funding for the nation's interstate system.

Under the state's proposal, truckers would have been charged $100 to travel the interstate in Pennsylvania. Motorists would have been charged $25 for the same privilege.

Jim Runk, president of the Pennsylvania Motor Truck Association, told the Wilkes-Barre Times-Leader that many members were concerned the proposed tolls would put truckers out of business or force them to leave the state. Runk told the paper that other states should get the message that "it's probably not good public policy to toll an existing highway that's part of our interstate system."

The DOT decision is a setback for those seeking alternate sources of revenue to pay for repairs and improvements to the interstate system. Fuel taxes, which haven't been raised at the federal level since 1993, will become a less-viable revenue source as vehicles become increasingly fuel-efficient, according to backers of alternate revenue mechanisms.

In a statement, Pennsylvania House Democratic leaders said the DOT decision "truly cripples the commonwealth's ability to repair and maintain Pennsylvania's roads and bridges—to say nothing of the negative impact the decision has on future road construction and mass transit systems statewide without an alternative source of funding."

This is not the first time a state has attempted to levy tolls on travel across the interstate system. DOT in 2003 approved Virginia's bid to implement truck-only toll lanes on parts of Interstate 81 running through the state. However, opposition to the plan eventually killed the proposal in the state. In 2005, DOT approved Missouri's plan for truck-only toll lanes on Interstate 70. It appears that project will move forward, even though it remains at this time in the "environmental review" phase.

According to NATSO, Wyoming is also exploring toll lanes on the section of I-80 running through the state.