AUGUSTA, Maine — A legislative oversight panel decided Tuesday it wants answers from the state’s transportation commissioner as it tries to determine whether the state Department of Transportation mismanaged a commuter van pool program that’s set to end Aug. 31.

The Legislature’s Government Oversight Committee decided against launching a full investigation into the transportation department’s management of the GoMaine Commuter Connections program, but members said they had questions about funding sources and whether the program had become unsustainable, as transportation officials have claimed.

“I think the questions are over in the DOT office,” said Rep. Chuck Kruger, D-Thomaston. “I don’t think there’s any great mystery. I think it’s fairly simple.”

Legislators on the panel were considering a request from Rep. Donald Pilon, D-Saco, to have the Legislature’s accountability arm investigate the management and operation of the GoMaine program and determine whether a $233,000 surplus in rider fees that has built up would be returned to the van pool’s 250 participants.

At a meeting last month, committee members asked the Office of Program Evaluation and Government Accountability to gather preliminary information on the program before deciding whether a full investigation was needed.

The Department of Transportation last winter announced plans to phase out the van pool service by May 1 and encourage riders to contract with private providers to resume their van pools. The department extended the end date to Sept. 1 after GoMaine riders asked for a year extension and the opportunity to work with program managers to find a way to sustain and expand the program.

Transportation officials made the decision after determining that the GoMaine van pool program — which serves about 250 commuters on 27 routes statewide and has a waiting list of about 250 people — couldn’t afford to replace all the vans that needed replacing while expanding the program to meet demand, Department of Transportation legislative and constituent services director Nina Fisher told the Bangor Daily News last month.

Lawmakers on the panel agreed Tuesday it wasn’t in their power to save the commuter program, but decided they still wanted accurate information about the program’s funding.

While riders pay monthly fees for the van pool service, the Department of Transportation covers about 60 percent of administrative costs, mostly from a pool of federal funds aimed at reducing traffic congestion. The Maine Turnpike Authority pays the balance, and the Greater Portland Council of Governments manages most of the program’s day-to-day operations.

“I just want to see the financials. There are a lot of people who depend on this to get to work,” said Sen. Nancy Sullivan, D-Biddeford. “I want to see it reinstated. I don’t know that I’ll get that.”