Chicago’s Union Station has a split personality. The Beaux Arts head house, which includes the Great Hall, is underused and often nearly empty. The underground concourse level, however, is overcrowded with passengers due to poor pedestrian circulation. Amtrak, which owns the station through a subsidiary, is seeking to remedy that situation with an RFP for the head house and an eventual redesign of the concourse. Meanwhile, the architect Helmut Jahn has proposed an alternative station as the hub of a new high-speed rail network.

While these projects are not in direct competition, Amtrak’s improvements and Jahn’s proposal come as the Obama administration has announced billions of dollars for high-speed rail infrastructure, including a Chicago-St. Louis link. This forthcoming investment underscores the need to accommodate a new and possibly expansive rail network within Chicago’s sprawling system.

Designed by Graham, Anderson, Probst & White, a successor firm of Burnham & Root, and completed in 1925, Union Station was diminished by the 1969 demolition of its aboveground concourse building, leaving the head house somewhat orphaned. Amtrak has invited seven architecture and real estate firms to respond to the RFP to redesign and reprogram the head house, including the architects SOM Chicago, KlingStubbins and Wallace Roberts & Todd of Philadelphia, Goody Clancy of Boston, and Ehrenkrantz Eckstut & Kuhn of New York, along with the real estate firms Jones Lang LaSalle and U.S. Equities Realty. “It’s very open-ended. The space is largely vacant,” said Marc Magliari, spokesman for Amtrak.

The railroad is studying the below-grade concourse, which was most recently renovated in 1991 by the architect Lucien Lagrange. A first-class passenger lounge and offices may be relocated to make room for additional bathrooms and passenger waiting areas. “We have outgrown our capacity in the concourse,” Magliari said, adding that Lagrange will likely be retained for that job.

At the same time, architects Murphy/Jahn are calling for a new station to accommodate high-speed rail trains to be built over existing north/south rail lines. Located near Union Station, the project includes a tower above and was designed for Reuben Hedlund, former head of the Chicago Plan Commission. “This was a proposal we put forth in response to a piece of property owned by our client, said Keith Palmer, a senior partner at Murphy/Jahn. “It’s an opportune site.”

Because Union Station is a terminal, Murphy/Jahn argues it would be ill-suited to an expanded high-speed rail network, while the new station could better facilitate rapid through trains from places like St. Louis that may some day continue on to points north, like Minneapolis or Detroit. Under the Murphy/Jahn plan, commuter rail would remain at Union Station.

Magliari points out that there are two north/south lines at Union Station, but he declined to speculate if that would be enough to accommodate an expanded high-speed network. The federal Department of Transportation recently allocated funds for a high-speed speed route to St. Louis with the expectation of connections to Minneapolis, Milwaukee, Detroit and other cities.

Rick Harnish, executive director for the Midwest High Speed Rail Association, thinks both plans are insufficient. “Improvements can be made at Union Station in the near term,” he said, such as moving some ticketing and lounge areas back into the head house. He doubts if the Jahn station would be large enough to accommodate a large train network and faults its location, which is hemmed in by the busy Congress Parkway and the Chicago River. “We really need the city to figure out what is needed and come up with a comprehensive plan. It’s crucial to the future of the city,” he said.