The federal highway trust fund is heading toward insolvency in late summer. The fund distributes about $50 billion annually to maintain and rebuild aging transportation infrastructure: crumbling bridges, pothole-pocked roadways. The debate over how to replenish it is about to begin.

U.S. Secretary of Transportation Anthony Foxx is hitting the road to make the case for more transportation funding. He is launching a national bus tour next week, to highlight the Obama administration’s emphasis on infrastructure investment - and its plan to finance it through corporate tax reform.

“We feel like this is a very important moment for infrastructure in this country,” Foxx said.

The administration is proposing a four-year, $302 billion transportation program that would replenish the highway trust fund plus an additional $90 billion. The push for corporate tax reform has some bipartisan support, as the Republican chairman of the House Ways and Means Committee, Congressman Dave Camp, has proposed a one-time tax on corporate profits held overseas to save the fund from insolvency.

The tour will begin in Columbus, Ohio, weave through eight states, and end in Dallas. Along the way Foxx will visit highway projects, freight rail facilities, and manufacturers to underscore the connection between transportation, economic growth, and quality of life. He said stabilizing the fund doesn’t go far enough.  

 “It is going to get us to a point where we can continue what we are doing, but what we are doing is insufficient when we compare it to what the future demands of us,” Foxx said.

Most of the money for the trust fund currently comes from the federal gas tax, but the rate has been $.18 per gallon for more than 20 years. Raising the tax to pay for transportation is a non-starter, with no support from the administration or Congress. The fund has limped along with short-term Congressional patches for the last five years.

“We are not in a political environment where Congress has shown an incredible willingness to think ten, twenty, thirty years out. Our proposal would get us not only restoration of the highway trust fund at current levels, but we also would invest $90 billion additional dollars over a four-year period. We think it is very important to have growth in our infrastructure investment,” Foxx said.

The president’s plan, with its proposed increase in both highway and transit spending, lays a foundation for a more comprehensive transportation program, he said. That comprehensive program, along with stable, assured federal funding, would let state departments of transportation plan long-needed large-scale projects.

“The crisis is we can’t make smart, long-term investment decisions when we don’t know where the money is going to come from,” said Joshua Schank, the president of the Eno Center for Transportation, a D.C.-based think tank.

If those long-term investments don’t get made soon, Foxx said, people across the country will bear the costs, in car repairs from damaged roads, and time lost to escalating gridlock.

 “The thing that is hardest to quantify and explain to people but is very real is the fact that our transportation systems always have to be built thirty years ahead of where we are. We have to be thinking about that as we build new assets today,” Foxx said. “We are going to experience massive population growth over the next thirty years, so whatever congestion is out there today it is going to get worse tomorrow if we don’t build for it.”