The state has proposed replacing the Thompson Center with a new skyscraper, shown here in renderings released by the governor’s office. Credit: Adrian Smith + Gordon Gill

Last month, despite marking two years as Illinois governor with no proper state budget, Governor Bruce Rauner struck an optimistic note when he floated a grand plan to replace the state-owned James R. Thompson Center with a 115-story skyscraper. I’ve nicknamed the proposed tower “Rauner’s Boner,” both for its rather phallic shape, and for the fact that historic preservationists argue that demolishing the existing postmodern structure, a unique design by Chicago architect Helmut Jahn, would be a serious folly.

But there’s another key factor to consider: In addition to state offices (and a groovy below-ground food court), the Thompson Center is home to the CTA’s Clark/Lake station, a crucial hub for transfers between the Blue, Brown, Green, Orange, Pink, and Purple Lines. It’s also a link in the Chicago Pedway system. We know the 1,700-foot structure would take years to complete. But what would be the impact on downtown transportation?

First, a little background on the proposal: On January 19 the governor’s office released conceptual renderings to suggest how the full-block site might be redeveloped. The aforementioned skyscraper would include retail, offices, apartments or condos, and a hotel and observatory, designed by local “starchitect” firm Adrian Smith + Gordon Gill. Another option shown features three towers of 40, 60, and 70 stories each.

Meanwhile, Clark/Lake was the CTA’s second-busiest station in 2015, with more than 5.5 million station entries. According to CTA spokeswoman Catherine Hosinski, since Clark/Lake serves six train lines, far more transfers are made at the stop than direct entries—about 1.4 transfers for every station entry.

Unfortunately, the government officials I spoke to this week were all short on details on how construction could be mitigated to keep the trains running smoothly. Hosinski wouldn’t comment on whether service at the station could be maintained during demolition and construction. She also declined to discuss the potential effects a huge new development could have on on train ridership and crowding.

“It’s far too soon to speculate,” she said.

Similarly, Mike Claffey of the Chicago Department of Transportation says it’s too early to comment on what impact redevelopment might have on the pedway.

At the state level, Rauner spokesman Mike Theodore says that “ensuring minimal disruption to the CTA and maintaining continued access to the Pedway are priorities,” but didn’t indicate how the state planned to go about this.

Despite this lack of detail, the renderings of the proposed plan do include some discussion of how the project could actually enhance transportation access on the site.

“Let’s hope we don’t have another showdown, as we did during the Trump Tower’s construction, due to the developer’s desire to short-change long-term transit needs.”

—Transportation expert Joseph Schwieterman

In the single-tower scenario, the edifice would be built at the south end of the property, near Randolph Street, with a freestanding “transit hub pavilion” located at the north end, near Lake Street, providing an entry to the subway and elevated trains. The three-tower site plan shows an office building at the south end and residential and hotel towers next to Lake, with a multistory atrium sandwiched between them, providing connections to all the el platforms.

Both scenarios could accommodate Mayor Emanuel’s (questionable) proposal for a high-speed rail line to O’Hare, and both would improve pedestrian connectivity by making it possible to walk diagonally across the block. They also appear to create more total plaza space than now exists, since the footprint of the relatively short, squat Thompson Center currently occupies most of the block.

“This creates a real opportunity to create more aesthetically pleasing spaces for [train] riders,” says DePaul University professor Joseph Schwieterman, an expert in transportation and sustainable urban development.

The Clark/Lake station during rush hour
The Clark/Lake station during rush hourCredit: Rich Hein/Sun-Times Media

Of course, Schwieterman adds, it all depends on whether a future developer will voluntarily act on that opportunity. During the planning of Chicago’s Trump Tower, he notes, there was a face-off between the city and the Trump Organization over preserving the Carroll Avenue Transitway, an old rail corridor that formerly served Navy Pier, which could someday serve as a new transit route. Ultimately, the city forced Trump to preserve the corridor, which added to the project’s cost.

“Let’s hope we don’t have another showdown, as we did during the Trump Tower’s construction, due to the developer’s desire to short-change long-term transit needs,” Schwieterman says.

There are also cautionary tales from other cities, where ambitious redevelopment plans have gone way over budget and dragged on for years, disrupting transit service in the interim. The Santiago Calatrava-designed transit station at the World Trade Center, for example, cost $4 billion and took 12 years to complete-vastly more than was first estimated. In San Francisco, the $2.25 billion multimodal Transbay Transit Center project has been plagued by funding shortfalls. While bus service is supposed to start this year, it’s unclear when or if planned rail service will materialize.

Still, it’s somewhat reassuring that there have been countless construction projects above CTA subway lines that went off without incident.

“Construction and demolition of buildings atop or adjacent to CTA rail lines is nothing new and CTA engineers work with developers each time to ensure that there is little to no significant impacts to rail service,” Hosinski said via e-mail, noting that the Thompson Center station is itself an example of this. The CTA previously had a separate Clark/Lake elevated station and the “Lake Transfer” subway station, both of which remained open to riders, with the exception of a few weekend closures, while the state offices and the 203 N. LaSalle building were being constructed. The two transit-oriented developments currently being built at Grand/Halsted/Milwaukee, above the Grand Blue Line station, are also examples of this, she noted.

Those examples suggest that a Thompson Center makeover wouldn’t necessarily lead to a transit apocalypse. Still, it will be important for citizens to monitor the planning process, and demand that any changes result in improved rail access. Since redeveloping the site seems to be a bit of a white whale for the governor, it’s vital to make sure any future project doesn’t wind up harpooning CTA service.   v

John Greenfield edits the transportation news website Streetsblog Chicago.