A new rail station at Baltimore/-Washington International Airport, linking trains on the Northeast Corridor to the growing airport, was dedicated officially yesterday and will be serving passengers beginning Sunday.

Located just off Maryland Route 170 near the I-295 BWI Airport exit, the $3 million Amtrak station is the nation's first intercity air/rail/ground transportation connection. The station, a mile and a half from BWI's terminal, will be served by free shuttle buses that will take 6 minutes.

Adjacent to Amtrak's Washington-New York-Boston corridor, the station will be served by both Amtrak and Conrail commuter trains. Generally, stops at the BWI station will be made by seven trains northbound from Washington and seven southbound from Baltimore on weekdays; at least four trains will stop in each direction on the weekends. There are 390 free parking spaces at the station.

From Washington, the 30- to 45-minute trip to BWI will cost $3.50 on the Conrail trains and $5.55 on the Amtrak trains; there are also some roundtrip excursion and weekly and monthly rates. The one-way fare by bus from downtown Washington to BWI is $6.50.

Although BWI is clearly less convenient than Dulles International Airport to many Washington-area residents, the new transportation link adds, another attractive feature to BWI, which recently has been gaining airlines and passenger traffic at the expense of Dulles.

The dedication yesterday was attended by Washington Mayor Marion Barry, Maryland Gov. Harold Hughes, Maryland's two senators, several congressional representatives and hundreds of others in government and in the air, rail and travel industries.