That analysis looks at ways to combine local, regional and national train and bus services onto the West Trade Street block now occupied by Greyhound.

The new station would replace the 1,200-square foot Amtrak terminal on North Tryon Street. Although Congress is debating the future of Amtrak, state officials are confident some sort of national train service will survive.

The new facility aims at providing a seamless connection between many forms of transportation. All five rapid-transit routes planned by Charlotte Area Transit System would link to the station. It would serve commuter rail from Davidson, local CATS and Greyhound buses, shuttles, taxis and rental cars. It would be CATS' second transit station uptown.

"People in Pineville could take light-rail uptown to catch a train to Washington or New York," said David King, an assistant state transportation secretary.

Currently, North Carolina is the only state considering such a complex project, engineers say. A few are expanding stations, but none involves the expense and difficulty of coordinating freight and passenger trains, and buses.

Fitting all that into one new building is all but impossible, say state officials, who think the operations will spread onto one or two adjoining blocks.

The feasibility study by the Charlotte office of Gannett Fleming, an engineering and planning firm, suggests seven possible ways to fit the station into uptown.

Now the state wants to narrow those options to two. A detailed engineering study would determine the site, layout and cost.

The N.C. legislature will vote later this year on taking that next step. Legislators haven't yet been asked to budget money for construction.

King expects construction in phases throughout the remainder of the decade. A start date has not been set.

The building should have enough room to meet the city and state needs for the next 50 years.

Planning has been under way for years, and the state has spent $22 million to buy 15 acres in the area bordered by the train track, Seventh, Graham and Third streets.

The state, federal government, Amtrak, CATS, freight companies, and office and retail developers would share the cost. The split hasn't been determined.

The study says the station would have seven tracks, three passenger platforms and about 40 bus bays. Additional platforms could be built at Ericsson Stadium and the uptown arena, if one is built nearby.

The planned station will not interfere with Charlotte's tentative arena plans, said Patrick Simmons of the N.C. Department of Transportation.

Retail shops, a bank, police substation and restaurants are planned, as well as a 4 1/2-acre park in nearby Fourth Ward. About 130 graves and unused gravesites at Elmwood and Pinewood cemeteries would be moved.

Neighbors, worried about the noise from trains and buses, want the state to close rail crossings at Brevard, Church, Seaboard and Ninth streets and include the Greyhound terminal in the main station.

They say the option of putting the bus station north of Trade brings it too close to future housing.