I definitely agree that the way we're funding highways and roads is absurd, and would love to see a gas tax where people paid for actual usage. I think the biggest obstacle might actually be the teamster's union...we've elected to use the highway system and trucks to move the majority of our goods (which is NOT how other areas do it) and let most of our freight trains rot away. The most damage to roads is caused by shipping and trucking, and they're paying a very small (proportionate to use) amount of road maintenance.
Itsjustme is absolutely right that we're subsidizing car drivers...but EVERYONE is subsidizing shipping and cargo.