New federal data shows that U.S. drivers continue this year to increase their use of the nation’s roads to new record levels, and therefore put more wear and tear on that infrastructure.

The Federal Highway Administration said its latest monthly “Traffic Volume Trends” report show motor vehicle traffic on all U.S. roads and streets grew by 2.2 percent in May, for an increase of 5.9 billion vehicle miles from the same month a year earlier.

That continues a trend in which motorists are steadily setting new record highs in traffic volume. In the first five months of 2017, the FHWA said, vehicle miles rose by 1.7 percent, after setting an all-time annual high during 2016.

In all, the report said, U.S. drivers racked up 281.2 billion vehicle miles during May, of which 195.6 billion was on urban highways and streets while 85.6 billion was on rural roads.

“The growing traffic volumes are no surprise to our members, the state departments of transportation, which are trying to maintain a stressed transportation system, to ease congestion and improve safety – despite constrained resources,” said Bud Wright, executive director of the American Association of State Highway and Transportation Officials.

“The data highlights what we have been telling the public and policymakers at both state and federal levels,” Wright told the AASHTO Journal, “that it will take greater investment in our transportation systems to both work down the backlog of worthy projects and keep up with growing demand.”

The continuing growth in traffic volume comes as President Trump has pledged to unveil a major infrastructure investment program that would improve highways and bridges, seaports and airports.

However, his administration has not yet offered details of those plans, beyond a brief outline in his budget proposal, nor offered ways to pay for it. And Trump proposed cutting some transportation programs starting in the budget year that begins Oct. 1, ideas that have so far received a mixed reception in Congress.

Meanwhile, industry groups including AASHTO have warned lawmakers that they need to act soon to head off a looming threat to the Highway Trust Fund, which is on course to run out of enough money to continue the current level of federal investment after 2020 unless Congress provides more revenue.

In a recent letter to Senate Finance Committee Chairman Orrin Hatch, R-Utah, AASHTO urged congressional tax writers to “consider supporting taxes or user fees” to put the trust fund on a solid financial footing for the long term.

And Pete Ruane, president of the American Road & Transportation Builders Association, has told lawmakers that unless Congress fixes the trust fund prior before 2019, it could leave the industry facing a new series of stop-start funding disruptions, such as state DOTs and other stakeholders suffered in the runup to the five-year surface transportation law Congress passed in 2015.

“The states will start to react to uncertainty over future federal funding as early as 2019, pulling back on project lettings,” Ruane warned. “This situation will put American jobs at risk.”