The State Infrastructure Bank has a new member with a good idea. Former state Commerce Secretary Joe Taylor wants the bank to finance only projects that are demonstrable transportation priorities. That’s the way to go, both for the SIB and the state Department of Transportation.

If the state is to get the most out of its severely limited resources for road and bridge construction, it will have to focus solely on priorities, both for new projects and for maintenance. Otherwise, the state will continue to see its limited road dollars diverted to politically driven projects that are nowhere near the top of the list.

That occurred with the I-526 extension, which isn’t even ranked as a state priority. Yet the state is prepared to fund the $558 million road across James and Johns islands because the State Infrastructure Bank made the decision to do so.

Mr. Taylor says a better place to spend the money would be widening I-26 from Charleston to Columbia. He won’t get any argument from those who regularly travel that road — particularly from Charleston to Summerville. And it will only get more congested with the expected increase in port traffic.

“You have to look at everything from a statewide perspective,” Mr. Taylor said in comments to the State newspaper. “When there are projects in the Midlands that have statewide ramifications or a state level of importance, there does need to be somebody in the Midlands who will advance those ideas and make sure that they get the same consideration as projects from other parts of the state.”

That latter remark presumably was a lightly veiled reference to the fact that the SIB board had been controlled by appointees of two powerful Charleston legislators. Before Mr. Taylor’s appointment, House Speaker Bobby Harrell and Senate President Pro Tem Glenn McConnell appointed a majority of the SIB board between them.

But Sen. McConnell became lieutenant governor when Ken Ard resigned, and this month the new president pro tem, Sen. John Courson, R-Richland, named two members, including Mr. Taylor. He opted to keep Sen. Hugh Leatherman, R-Florence, on the board.

Mr. Taylor’s view on prioritizing highway projects should prevail generally on highway projects in a state with so many transportation shortcomings and such inadequate funding.

The willingness of the state highway commission to avoid that goal was evident in 2011 when it voted to use $344 million to build five road projects, only one of which was a state priority. Faced by public criticism and financial problems, the commission abandoned that plan late last year.

But there’s nothing that says the commission or the SIB couldn’t do the same again. The Legislature should patch that hole in its 2007 reform of the DOT so that an objective test of priority is applied whenever decisions are made to build roads and bridges in South Carolina.