source of funding for building federal highways. >> states have their own gas tax as well and a number of places like montana and south carolina, they have increased there is in recent weeks. if you're getting regular gas, american say about $0.50 in state and federal tax on every gallon. for diesel, the average is $0.55 per gallon. >> heather: does anyone in the congress support increasing the federal gas tax? speak out senators from wyoming say they do not support increasing it. paul ryan and mitch mcconnell have also been against it in the past. there tends to be more support for it on the left, but one republican from south carolina representative tom rice, it introduced a bill back in 2015 to increase the gas tax. you're driving today, it is cheaper than it was this time last year.