The incoming president of the U.S. may win the prize for Toughest Job in the World, but the chief executive officer of the Honolulu Authority for Rapid Transportation? That’s pretty tough, too.

So it’s reasonable to ask whether Lori Kahikina, the newly named interim HART chief and the city’s outgoing environmental services director, is equipped for the job she took over on Friday, on a one-year contract.

Some people already are asking. One is state Sen. Lorraine Inouye, chairwoman of the Senate Transportation Committee, who said Kahikina lacks credentials and connections with federal partners on the rail project.

Kahikina, named on Tuesday by the HART board, succeeds Andrew Robbins, whose place at the agency helm was not renewed. Inouye said she was concerned that the new CEO has no experience in this infrastructure sector.

But Kahikina has her defenders as well, including Panos Prevedouros, someone who is no great fan of the 20-mile rail project Kahikina will oversee, but believes her knowledge of the city will serve her. Prevedouros is a civil engineer and professor at the University of Hawaii, where Kahikina earned her mechanical engineering degree.

And Kirk Caldwell, who today officially hands over the keys to new Mayor Rick Blangiardi, told the Honolulu Star-Advertiser editorial board that Kahikina has managed projects such as the sewer- system’s $5.5 billion rebuild, and ran a department of 1,000.

She is not the first city administration member to take that interim HART post: Mike Formby, former city transportation director (and now Blangiardi managing director) preceded Robbins.

However, this is undeniably a precarious juncture for the rail project, needing the release of remaining federal subsidy and a financial plan that passes muster with the Federal Transit Administration.

Kahikina herself acknowledges she will need to earn people’s trust — and that will be a high hurdle. Robbins heaped praise on the HART team, and Kahikina’s ability to work with that team will be key, especially in getting ready for the partial launch of the system later this year.

Her experience with the city also may give her a well-timed boost. In a year, when she’d be up for renewal, contractors may be undergrounding the utilities along the challenging Dillingham Boulevard rail corridor. Kahikina knows about some of the danger spots, or could find someone who does at the Municipal Building.