Currently, a round-trip weekend ticket from Penn Station to Union Station costs a minimum of $32 on Amtrak. The same trip on MARC on a weekday costs $14, not counting discounts for monthly passes. A one-way Amtrak ticket from Baltimore-Washington International Thurgood Marshall Airport to Washington costs $15; the MARC fare is $6.

"It's a major boost for BWI," Guroian said.

In addition to weekend Penn Line service, the MTA also announced plans to add two runs each weekday to its Camden Line service.

Owens said monthly passes will be valid on weekend trains once that service starts. He said that under the transportation bill, MTA fares will rise by $1 per trip in July 2014.

In addition to the new funding for MARC, the MTA announced that $450 million of the spending announced Thursday would go toward completing the design of three high-priority transit expansion projects. The Red Line will get $170 million, while the proposed Purple Line between New Carrollton and Bethesda will receive $280 million. Another $100 million will go toward a transit line in Montgomery County's congested Interstate 270 corridor.

Mobley said the new design money would not speed the projects but would allow the MTA to keep moving forward on them. He said the state still hopes to start building the Red and Purple lines in 2015 and to complete them in 2020, but the projects still must compete for federal construction dollars.

The highway spending announced Thursday includes some long-delayed safety and expansion projects across the state.

The big items in the Baltimore region are $60 million to rebuild the Leeds Avenue interchange with the Beltway in Baltimore County, $44 million for intersection improvements around Aberdeen Proving Ground in Harford County, and $49 million for widening northbound U.S. 29 in Howard County between Seneca Drive and Route 175 to three lanes.

The U.S. 29 project was a top priority of Howard County Executive Ken Ulman, one of the top local elected officials who lined up in support of O'Malley's transportation bill.

"As anyone who has sat in traffic there knows, removing this bottleneck will allow parents to get to their kids' schools and games quicker, get home to their families sooner and generally make life easier for so many of us," he said.

Key bills signed Thursday

Gov. Martin O'Malley signed more than 200 bills into law Thursday, including these:

Gun safety: Bans sale of guns classified as assault weapons. Bans sale of magazines with more than a 10-bullet capacity. Imposes new licensing and training requirements on purchasers of handguns. Also includes provisions intended to keep guns from people considered dangerously mentally ill.

Transportation funds: Raises taxes on gasoline by estimated 13-20 cents a gallon by 2016. Requires increase in MTA bus, subway and light rail fares.

Baltimore schools: Authorizes Maryland Stadium Authority to issue $1 billion in bonds to launch six-year program to rebuild Baltimore school buildings.

Cellphones: Allows police to pull over motorists for using hand-held wireless devices while driving even if no other offense is being committed.

Human trafficking: One bill allows seizure and forfeiture of property used in human trafficking. Another prohibits ignorance of age of victim as a defense.

Pet population control: Establishes a spay/neuter fund for sterilization of pets to be financed with a fee on commercial pet food.

—Erin Cox