Here is a pretty good summary of the bleak outlook for funding state roadways. The issues is that the gas tax is a bad revenue source for a number of reasons. The biggest issue is that maintaing our roads is getting more efficient but the gas tax revenues are declining. People are driving less and the vehicles they are driving are getting far more expensive. Without change and new revenues we wont maintain what we have let alone improve Highway 14 or other highways.
Some people complain that a portion of the gas tax funds some ped / bike safety improvements and transit. This is mostly a distraction because the places that tend to use these funds are in general paying more in taxes to subsidize rural road dependent areas.
My preferred solution is one that everyone hates. I would like to see cars pay a user fee based on miles traveled and vehicle weigh. In my book it is the fairest of all options. The technology exists and this would solve the issues.
Here is the MnDot Info: MnDot Funding Gap