It has been about 13 years since I have been up there. I don't know if any of our income tax goes to road, probably to state roads. I expect at least some of it does. I think most comes from gas tax (which really should be raised since it is "per gallon" and not indexed to inflation). County roads come from the county portion of property taxes as does city portion.
There is a continuous push to implement a sales tax here in addition to the state tax but it always gets voted down. This would just be a tax increase that would be bickered over for usage. Much better to just increase the gas tax and use it for roads.