Dignity has been restored to the rails in downtown St. Louis. For more than 25 years, until recently, boarding Amtrak in the city involved not a station but the “Amshack,” a modular number hidden under the freeway on what looked like a set from The Wire. You would buy your ticket and pray the wait wouldn’t be long. Then you had to make your way through a treacherous gravel yard to reach your train. All along, there was a wonderful Romanesque train station nearby: Union Station, opened in 1894, was once the world’s biggest and busiest station. It closed in 1978 and reopened in 1985 as a hotel and shopping mall, but—this is the sad part—without trains. In 2004, the local Riverfront Times reported that the Amshack was “thought to be the oldest temporary depot in the world.”

How far things had fallen in the way of railroad romance. But they have now swung upward again with the completion of the St. Louis Gateway Transportation Center, a new downtown depot built to serve Amtrak. It’s not Union Station’s limestone castle, but, with 16 trains a day, St. Louis can live with less, and these days, two platforms serving four newly built tracks is enough. More important than capacity are the connections. The Gateway Center, which cost $27 million, gives Amtrak passengers a modern portal but also direct access to MetroLink, the local light rail system, and to Greyhound buses.

Fitting these functions together on the site that was available took surgical skill, because Metro, the local transit authority, owned only one parcel downtown where all three transit systems met. It happens to be directly beneath four overpasses of Interstate 64, so the 35,700-square-foot building appears to have been slipped—or poured—around several of their columns.

“It wound up being a very curvilinear project because of all the site constraints,” says Melissa Kreishman, the project architect at KAI Design & Build, a St. Louis firm that led the Gateway station’s design. The building stretches 700 feet, with angled façades and windows laminated in syncopated Mondrian-like colors to suggest the notion of movement. Along the north wing are Greyhound’s operations, including 10 bus bays and turnaround space. At the far northern end is a sidewalk crossing to MetroLink trains and the MetroBus station. The south wing extends an enclosed skywalk over the Amtrak lines and down to the two platforms. Between the wings lies the main ticketing and waiting area, with a broad view north toward downtown.

There were constraints on the ground but also from above: There is constant highway noise to keep out and huge loads of plowed snow that may crash onto the building from the overpasses. So the building needed a certain amount of armor for the harsh environment.

“It was not easy squeezing the project onto that site,” affirms Tom Behan, the city’s chief construction engineer. “But it’s now a whole lot neater than what was there.”