In a statement, Shuster said, “Rather than focusing on a re-election campaign, I thought it wiser to spend my last year as chairman focusing 100% on working with President Trump and my Republican and Democratic colleagues in both chambers to pass a much-needed infrastructure bill to rebuild America.”

Shuster came to Congress in 2001, succeeding his father Bud, who chaired the infrastructure committee from 1995 to 2001.

Shuster has been successful in getting major infrastructure bills through Congress, “and he did it in a bipartisan way," notes Jay Hansen, National Asphalt Pavement Association executive vice president.

"We're sorry to see him go," says Steve Hall, American Council of Engineering Companies vice president for government affairs. "He's been an incredibly effective chairman in maneuvering major pieces of legislation through a difficult Congress--far more difficult than what his father had to deal with."

Shuster’s achievements include the 2015 Fixing America’s Surface Transportation, or FAST, Act. It authorized highway and transit programs for five years, but industry officials found its $305-billion total disappointing. Shuster also played a key role in passing water-resources bills in 2014 and 2016, authorizing billions for Army Corps of Engineers projects.

Shuster hasn’t been as successful so far in his push for another of his priorities—a plan to spin off the Federal Aviation Administration’s air-traffic-control operation into a nonfederal entity. The plan has run into opposition from other lawmakers, such as Sen. Bill Nelson (Fla.), top Democrat on the Senate commerce committee.

Construction industry officials continue to await more details about Trump's infrastructure proposal. The president had pledged months ago that he would roll out a $1-trillion plan, but it was bumped to the back burner by an unsuccessful effort to undo the Affordable Care Act and a successful push to pass a tax-cut bill.

Administration officials have said the proposal would include $200 billion in direct federal spending, but where those funds will come from, or how they would be distributed, remains unclear.

Hansen says that on infrastructure legislation, congressional Republican leaders first must agree on what they want to do. He adds, “As I understand it, they’re not on the same page” on that issue.

Hansen praises Shuster's legislative skill. But he also notes that Congress will not have many days in session during this election year to pass major legislation. “I think the window will close quite rapidly,” Hansen observes.

Looking ahead to who might succeed Shuster in holding the "T&I" Committee gavel, if Republicans hold a majority in November's elections, "We've got two very able lawmakers vying to replace him," says Hall. He is referring to Reps. Sam Graves (R-Mo.), who chairs the highways and transit subcommittee, and Jeff Denham (R-Calif.), who heads the railroads, pipelines and hazardous materials subcommittee.

If Democrats gain a majority, the committee's ranking member, Peter DeFazio (Ore.), would be the likely choice as the panel's chairman.

Story updated on 1/3/18 with comments from ACEC.