A tax on how much you drive — could it happen in Illinois?

The Illinois gas tax was last increased in 1990, from 16 cents a gallon to 19 cents.

In that year, East and West Germany reunited, Nelson Mandela left prison and Andre Dawson played for the Cubs.

It was, in short, a long time ago, and the tax has not kept up with inflation. Some lawmakers pushing for a capital bill want a hike in the current gas tax, which helps pay for construction and repair of state’s roads and bridges.

But the gas tax has another problem. More fuel-efficient cars mean drivers buy less gas and that means lower gas tax proceeds. As a result, some states have looked into an alternate road use tax, charging by miles driven.