But it adds that “even these estimated investment levels may be inadequate,” noting that the figures don’t include the costs of reconfiguring and rebuilding many of the approximately 15,000 interchanges on the 46,876-mile Interstate system, or the costs of making the system more resilient.

The report's release comes at a time when President Trump and Senate and House leaders have been saying infrastructure may be one of the areas of bipartisan agreement in the new Congress.

The study also could be part of the debate on Capitol Hill over the next multi-year surface-transportation authorization bill, covering highways and transit. That new measure would succeed the 2015 Fixing America's Surface Transportation, or FAST, Act, which expires in 2020.

The "Interstate Renewal and Modernization Program" that the report’s authors envision would concentrate on rebuilding Interstate pavements (including foundations) and bridges; adding capacity and the capability for tolling and other demand-management techniques; and making the system better able to cope with extreme weather and other effects of climate change.

Paying for infrastructure programs has long been the critical issue. To raise the new revenue, the report’s authors recommend raising the federal motor-fuels tax up to the federal share of the new program’s total spending, plus increasing that levy for inflation or for changes in motor vehicle fuel-economy.

The report, which Congress requested in the FAST Act , also suggests other funding options, such as ending the general prohibition on putting tolls on existing Interstate highways and adding new per-mile charges for highway travel.