Metro will hold town-hall meetings and public hearings in mid-May on possible service cuts and other measures to help close a $72.5 million operating budget gap for the fiscal year that begins in July.

The shortfall in Metro’s fiscal 2012 operating budget of $1.4 billion resulted from several factors, including slower-than-projected revenue growth of $23.8 million caused in part by last year’s fare increases as well as $16 million in expenses carried over from last year’s snowstorms.

The proposed service cuts that will be on the docket for public hearings — scheduled for May 16 through May 20 — would not be implemented until September. They include reductions in weekend rail service that would save Metro about $6.6 million. The cuts would increase the time between trains on Saturday and Sunday by five to six minutes during the day and up to 25 minutes after 9:30 p.m.

A last-minute bid to eliminate the rail portion of the service cuts failed after the Metro board voted down an amendment by two of the newest board members from Maryland, Michael Barnes and Alvin Nichols, to remove them.

“The service on weekends is already about as inconvenient, in terms of headways, as we want to have it,” said Barnes, who was attending his first board meeting.

Other board members argued that with jurisdictional budgets tight, all options needed to remain on the table for public discussion.

A proposal to eliminate some bus routes would save an additional $1.26 million. Metro bus routes singled out for cutting include the K1 route between Takoma Park and Walter Reed Army Medical Center, the N8 between Tenley and Glover Park, and the E6 in Chevy Chase. In addition, an extension of the M4 line along Nebraska Avenue would be halted.

A third proposal would eliminate a customer discount by ending a 50-cent-per-trip subsidy by the District for bus riders in Anacostia, which dates from the extension of the Green Line in the early 1990s.

The District wants to recoup that money to use toward its contribution to Metro’s operating budget.

After the biggest fare hike in Metro history last year, the board has ruled out fare increases as a way to close the budget gap. Earlier on Thursday, the board’s finance panel discussed a proposal by the advocacy group Transit First to increase parking fees by $1 in Metro lots that regularly fill up but ended up tabling it.

The finance panel also decided to put off considering a 5-cent surcharge per trip on all riders using Union Station. Union Station is the busiest station in the Metrorail system, and the charge would have affected about 68,000 people a day.

The surcharge concept was approved by the board last year as a way to fund station improvements, and the Union Station plan marks the first time the board has considered exercising the option. Members from Maryland and Virginia, however, were concerned that the board had not adequately discussed the criteria for using the surcharge, according to board member Tom Downs of the District.

The finance panel did approve a $2.5 million plan to be funded by the District to increase Union Station capacity. The plan, which will go before the full board April 28, would add escalators and elevators and expand the station’s platform, mezzanine and concourse.

Downs said he thinks that the improvements should qualify for the surcharge.

“This is a regional station. It shouldn’t just be a D.C. project,” he said.