Robert St. Onge made an early exit as secretary of transportation for the state of South Carolina on Friday after he was charged with driving under the influence. His departure is unfortunate, but the administration properly regards the DUI arrest as a disqualifying event for a Cabinet head.

Mr. St. Onge, a retired Army general, was picked up Friday morning by the highway patrol and charged with DUI. By Friday afternoon he had resigned his post.

Though his departure occurred under a cloud, as transportation secretary Mr. St. Onge brought a welcome sense of reality to the department's funding problems.

They dramatically surfaced during his first year on the job when it was learned that the DOT hadn't kept pace on its payments to contractors, leaving some in a difficult financial position. He quickly came to grips with the matter, making sure that contractors were paid on time and that the DOT was made more financially accountable for the future.

But the larger inability of the DOT to keep pace with road and bridge needs without increased funding was more than Mr. St. Onge could effectively handle. He often declared that, absent additional resources, his job would be "to manage the decline of the state highway system."

Part of the DOT's problem has been the willingness of the highway commission to give a nod to politically driven projects, rather than demonstrable priorities. Priority funding for road and bridge projects was a central aim of the 2007 reform of the agency, but even after passage of the reform bill, the commission retained leeway to act independently of the state priority list.

Nowhere was that more evident than in the $344 million bond issue sought in 2011 by the commission for five major highway projects, only one of which was on the state priority list. That proposal quietly advanced, and the bonds almost certainly would have been issued had it not been for Commissioner Sarah Nuckles, who blew the whistle on a bad deal. She noted that the bond issue would virtually consume the state's remaining borrowing capacity for highways - a real problem in the event of an emergency.

Under the harsh glare of public scrutiny, the commission backed off the proposal.

The DOT did receive a $600 million infusion of tax money during the last legislative session - though still not the gas tax increase required to deal with road and bridge needs estimated at $29 billion.

Although Mr. St. Onge was Gov. Nikki Haley's appointee, he worked for the highway commission as well. It's a difficult job to serve two masters, and the next reform of the DOT should consider the situation.

Of course, without legislative action this year, the 2007 reform will "sunset" in January under the terms of that bill. Then the DOT would no longer be a Cabinet agency, but return to the pre-2007 status quo, when the state's chief executive wasn't even in the picture in regard to the road agency.

The state's highway agency needs further reforms, not a return to the days when the commission was strictly the creature of the Legislature.

Such backsliding would simply make matters worse, and responsible lawmakers shouldn't allow it to happen.