As President-elect Trump’s pick for transportation secretary, Elaine Chao will face challenges on multiple fronts, including how to regulate self-driving cars, how to deal with growing numbers of vehicle recalls and how to modernize the nation’s air traffic control system. But her most high profile role in the new administration could be in helping rebuild the nation’s infrastructure if Trump follows through on his promise to invest $1 trillion in bridges, roads and airports.

Chao served as deputy secretary at the Department of Transportation in George H.W. Bush administration and had previously worked as deputy administrator of the Maritime Administration, another department within DOT before being tapped to be secretary of labor in George W. Bush’s administration.

“Coming in with that prior experience at DOT and as a cabinet secretary, it gives her a running start on whatever it is that she and the president want to achieve,” said former Metro board chairman Mortimer L. Downey, who succeeded Chao as deputy transportation secretary.

Perhaps the biggest concern for the Washington region will be how active a role she will take in the rehabilitation of troubled Metro system, which has been under federal safety oversight for more than a year. Transportation Secretary Anthony Foxx has been both a supporter and vocal critic of the system saying that regional leaders must take more responsibility for its upkeep and safety oversight.

Former transportation secretary Samuel Skinner, who recruited Chao to be his deputy at DOT, said Chao will recognize that Metro isn’t working and needs to be dealt with.

“It’s something she’d definitely be interested in doing,” he said.

An early signal may come in February. Foxx has threatened to pull millions in funding for transportation projects in the District, Maryland and Virginia if officials fail to create a state safety agency to oversee the transit agency. Officials have already said they will not make the deadline so it will be left to Chao to determine whether to yank the funding or grant officials an extension.

Chao also could wade into the debate over Metro oversight — specifically whether it should be shifted from the Federal Transit Administration to the Federal Railroad Administration. The National Transportation Safety Board issued an urgent recommendation last year calling for the change, a shift NTSB said would put Metro oversight under a better staffed, more experienced agency and eliminate the need for a separate state-based agency. Moving Metro oversight under FRA, however, would require Congressional approval.

In addition to safety oversight, some members of Congress say that the new secretary must free up more federal dollars to pay for Metro.

“The challenge facing the new transportation secretary from day one will be to increase federal support for Metrorail and resolve long-running questions about the ability of the FTA to provide robust safety oversight of our nation’s transit system,” said Rep. Gerry Connolly (D-Va.). “The federal government can no longer be a deadbeat when it comes to support for Metrorail, and I look forward to working with the new transportation secretary to secure appropriate federal support for the very transit system that delivers many DOT employees to work each day.”

Even so, calls for additional federal support are likely to face strong opposition in a Republican-controlled Congress.

And Metro isn’t the only transportation issue on legislators’ minds.

“Transportation and infrastructure are major priorities for Northern Virginia,” said Rep. Don Beyer (D-Va.). “I have been working hard to secure funding to repair Arlington Memorial Bridge, to help build a safer and more reliable Metro system for the Capital region including a dedicated federal funding stream, and to reduce the noise emitted by aircraft flying in and out of [Reagan National Airport]. We need the Department of Transportation to be a diligent partner to achieve these goals, and I hope that Elaine Chao will be able to bring her considerable D.C. experience working under two previous administrations to bear in helping us solve these problems.”

Word of Chao’s appointment, however, was greeted with skepticism from some union groups, including the main union representing Metro employees.

“The appointment of Elaine Chao as Secretary of Transportation by the President-Elect is concerning to ATU Local 689 given that she was found to have inadequately investigated pay shortages of wages and overtime of workers as President George W. Bush’s Secretary of Labor,” the union said in a statement. “We have no reason to believe she will stand up for working people now.”

Chao previously served as a director at Northwest Airlines, where she was granted a lifetime travel benefits before the airline was acquired by Delta. She also was a former director at Parsons, the international construction company, experience that could prove particularly relevant given Trump’s promised infrastructure push.

“I am pleased that my friend Elaine Chao is once again willing to serve the country and has been asked to be the next Secretary of Transportation,” said Rep. Barbara Comstock (R-Va.) “Secretary Chao is a leader with a strong management and policy background and is a great choice to lead this important agency that will be very active in the coming years.  I look forward to working with Secretary Chao on a number of important transportation issues that impact our region including reforming Metro, easing traffic congestion, and modernizing and rebuilding our infrastructure.”

Ashley Halsey III and Michael Laris contributed to this report