Commuters riding MARC's #432 train between Union Station and Baltimore. (Photo by ASTRID RIECKEN For The Washington Post)

Weekend MARC train service between Washington and Baltimore, which has never been offered before and has long been desired by riders, is set to begin on Dec. 7, Maryland Gov. Martin O’Malley (D) announced Wednesday.

The service is one of several newly funded projects throughout the state resulting from a major transportation funding package, passed by the Maryland General Assembly this spring, that will gradually increase gas taxes and raise a projected $4.4 billion for new projects over the next six years.

During an afternoon event at a MARC station in Baltimore, O’Malley highlighted $1.5 billion in transportation spending in the city and surrounding counties, part of his rollout of newly funded projects throughout the state. The Baltimore package includes a preliminary commitment to fund construction of the proposed light-rail Red Line, according to administration officials.

O’Malley has previously spotlighted new spending benefiting Prince George’s and Montgomery counties, including investment in the proposed light-rail Purple Line.

Upon signing the transportation legislation in May, O’Malley pledged to expand the Maryland Transit Administration’s MARC service to include weekend trips on the Penn Line between Penn Station in Baltimore and Union Station in Washington.

Wednesday marked the first time O’Malley has provided details of the $46 million expansion, an aide said. Plans calls for nine round trips on Saturdays and six round trips on Sundays.

Riders have long sought the weekend service, which is expected to help people who work on Saturday or Sunday or need to reach Baltimore-Washington International Marshall Airport. Current MARC riders and transit advocates welcomed the announcement of a start date for the service.

Rafi Guroian, chair of the MARC advisory council, said riders have wanted the service for a “very long time” and that officials were “close to implementing it back in 2008, but then the budget crisis happened.”

“They had to reel in budgets,” he said and the service wasn’t started. “We’ve been crawling our way back ever since.”

He said MARC is “one of the few commuter rail lines in the country that does not have weekend service.”

One major attraction for many MARC riders is that the fares for the weekend would be less expensive than on Amtrak. Amtrak can run between $16 and nearly $50 one-way for a weekend trip between Baltimore and Washington. The rates for the MARC weekend service haven’t officially been set, but advisory council members said they expect the fare will be $7 each way — the same as on weekdays.

“To be able to take a MARC train for much less is going to be a no-brainer for people who need to make those trips on weekends,” Guroian said.

Ben Ross, a transit advocate, said the addition of weekend service on MARC makes it “a real railroad.”

“This is a game changer for stations along the [Baltimore-D.C.] line,” he said. “You’ll be able to live there without a car and get to D.C. and Baltimore every day of the week. It will be a seven-day-aweek transportation service as opposed to something that just takes you back and forth to work.”