Starting in September, the Massachusetts Bay Transport Authority (MBTA) will keep buses at popular T stations running until 2:30 a.m. on Friday and Saturday nights as part of a one-year pilot program to test the financial viability of late night public transportation.

Now, Cambridge Representative Alice K. Wolf is pushing to keep both buses and subways running late seven days a week.

Yesterday at 10 a.m., Wolf presented a bill to the legislature’s Joint Committee on Transportation proposing that the T remain open until 2:30 a.m. every day.

But members of the committee say they’ll probably adopt a wait-and-see approach.

“I think what’ll happen is we’ll probably hold this [bill] until it [the pilot program] works out,” said Robert A. Havern ‘73, Senate Chairperson of the committee, in an interview yesterday.

The MBTA pilot program—which has been planned for four years—will start with buses rather than the subway for cost reasons.

“Most of our buses are much more energy-efficient [than subway cars],” Havern said.

Many of the late-running buses will cover heavily-trafficked areas, including those used by Harvard students.

“One of those bus routes goes right out to Harvard Square,” Havern said.

But critics of the pilot program point out that similar pilot programs attempted in the past never got off the ground.

“There have been plans [to start a pilot program] for the past two years” said Wolf. “I’ll believe it when I see it.”

The union representing the workers who staff public transportation—Carmen’s local 187—is in favor of extending the hours, according to Havern.

“The union is going to try to work with us,” said Havern. “If they’re on board, it’s obviously going to be easier.

While cost considerations are the largest reason the T is not open late at night, Havern says the 12:30 a.m. closing time seems to be fairly arbitrary.

“It was probably some puritanical opposition that happened 100 years ago,” he said.

—Staff writer Lauren R. Dorgan can be reached at dorgan@fas.harvard.edu.