President Trump’s infrastructure investment proposal has moved to the next step—congressional scrutiny—and faces what looks like a steep uphill path to enactment.

As congressional committees begin hearings on the plan, questions persist about the source and size of the plan’s funding. Moreover, the election-year congressional schedule remains tight. A key House infrastructure advocate, Transportation and Infrastructure Committee Chairman Bill Shuster (R-Pa.), says action on a wide-ranging measure encompassing highways, waterways, drinking-water, wastewater and other programs may have to wait until a possible lame-duck session.

But prospects are much brighter for more narrowly focused infrastructure legislation. The likeliest item is a $10-billion boost for infrastructure that congressional leaders agreed to insert in appropriations covering the rest of fiscal year 2018. That legislation could emerge as early as late March.

Beyond that, Shuster and his Senate counterpart, Environment and Public Works Committee Chairman John Barrasso (R-Wyo.), say they plan to pass a new water-resources measure this year that would authorize billions of dollars toward Corps of Engineers flood-control, environmental and other projects.

Also coming up this year is a Federal Aviation Administration bill that includes authorization for airport construction grants.

A large share of any infrastructure omnibus and of the $10 billion in 2018 appropriations is likely to go for highways and bridges, the largest federally supported construction program. The legislative prospects for surface transportation were the center of attention as the American Association of State Highway and Transportation Officials gathered in Washington, D.C., Feb. 27-March 2 for its winter meeting.

State department of transportation leaders heard from key Senate and House infrastructure committee leaders from both parties and from U.S. Transportation Secretary Elaine Chao. Some state officials say they heard optimistic notes in the speakers’ remarks, but it also was clear that passing a wide-ranging infrastructure measure this year is a long shot.

Steve Ingracia, Nebraska DOT deputy director for technology and strategic planning, says, “I guess anything is possible, but I didn’t hear a lot of optimism that it would happen this year.”

Shawn Wilson, secretary of the Louisiana Dept. of Transportation and Development, says the congressional speakers provided “a really good dose of reality to speak to the challenges of really funding the needs of this country as well as putting together a bill that’s going to earn votes.” Wilson adds, “And we’ve got a little ways to go.”

Trump on Feb. 12 unveiled a detailed blueprint of what he says is a $1.5-trillion, 10-year proposal, of which only $200 billion would be direct federal funding. Half of the $200 billion would be grants to states or localities, with a large non-federal matching share required. Another $50 billion in grants would go to states for rural projects. It would leave the Highway Trust Fund in place.

The plan also calls for steps to speed federal project reviews. AASHTO strongly supports policy changes to get projects approved faster, says Bud Wright, executive director. But he adds, “We recognize, too, that process reform doesn’t substitute for funding. At the core, we need more dollars in the system.”

Moreover, if a sweeping infrastructure package emerges, AASHTO wants to see as much of the surface-transportation portion as possible distributed by formulas, as it has been for many years.

The prime issue for state DOTs is solving the Highway Trust Fund’s long-standing revenue shortfall. John Schroer, Tennessee DOT commissioner, says, “We do what we do based upon the trust fund.” Schroer supports including some grants in a national plan, but not a major shift to U.S. DOT grants for which states have to compete. “It will hurt immensely, especially the middle of the country, the rural states,” he says. In Tennessee, Schroer says, “We can’t work off of a grant program. We don’t have projects that ring the bell.”

Gasoline Tax

One possible trust-fund “fix” would be raising the 18.4¢ federal gasoline tax, last increased in 1993. It is the trust fund’s main resource. At a Feb. 14 White House meeting, Shuster and other lawmakers heard Trump float the idea of a 25¢ gas-tax hike. Shuster has talked about a 15¢ boost. He conceded an increase would be difficult to pass. But he added, “We’ve got to get serious. A conservative principle is, if you use something, you pay for something.” Chao told a House transportation committee hearing March 6 that when it comes to “pay-fors” to fund an infrastructure plan, “Everything is on the table.”