The Iowa Department of Transportation is floating a number of ideas to come up with more money for road construction.
The DOT is currently running about $200-million short of the money needed to pay for road repairs.
Officials say the shortfall is partly due to increasingly efficient vehicles with motorists having to buy less gas and the fuel tax associated with it.
According to Radio Iowa, the DOT is pitching two proposals to Iowa lawmakers to make up for the shortfall.
One option would eliminate the tax-exemption for diesel fuel used in tractors and road construction equipment. That could raise $38-million a year.
Another option is to raise the state tax on vehicle purchases. That could bring in another $60-million.
Both proposals would need legislative approval.