Oregon’s gas tax increases by six cents as of January first. It's the first state gas tax bump since 1993. State Representative Jefferson Smith, a Democrat, voted against the increase in the gas tax two years ago but says the billion dollars raised over the years will provide hundreds of jobs. Smith says the tax will pay for 37 projects around the state, largely improvements to highway bypasses and interchanges. The tax increase is expected to cost the average driver $30 dollars a year.