"It's one of the busiest stations on the Penn Line," said Jack Cahalan, department spokesman. "As we try to provide more transit options for people with the goal of getting more cars off the road, you have to make transit accessible, you have to make it efficient and you have to make it an enjoyable experience."

The state's broad plan includes a new station building, a fourth track and a third platform. The grant application is included in the state's bid for $360 million in federal stimulus funds for the Amtrak and MARC commuter rail system throughout the state.

"One of my top priorities is creating a more balanced transportation network by investing in all forms of public transportation," Gov. Martin O'Malley said in announcing the application.

Other projects in the state proposal include a tunnel replacement in Baltimore, several rail bridge replacements, construction of a train storage yard, a GPS train locating system and other improvements. BWI is one of two $10-million projects - cheap compared to the other major requests.

The expanded BWI rail station would be about twice the size of the existing one and built to more environmentally friendly specifications, Cahalan said.

The plans call for an expanded waiting area with more ticket kiosks and a larger concession area. New pedestrian walkways above the tracks would be built, a new fourth track and third platform would be added and existing platforms would be modified to allow access to at least three of the tracks.

Cahalan said the expansion would be within the existing footprint of the station's property off Aviation Boulevard in Linthicum and should not impact the surrounding area.

Cahalan is not sure when the state will know if the application is approved, but said the study would take years.

In recent years, a parking garage has been added at the station. Federal funding has been approved to expand and renovate the elevators at the station.