Here is an inside look at the partly completed Block 37 CTA station that was once intended to be home to express service to both Chicago airports:

The superstation, which was mothballed in 2008, runs on a diagonal from beneath the corner of Randolph and Dearborn streets, southeast to the corner of State and Washington streets. I’m not supposed to say how you access the space — security concerns, you know — but let’s just say that a variety of elevators, locked doors and ladders are involved.What’s striking once you get in the space is its size: as long as a football field-and-a-half (472 feet), 68 feet wide and averaging 28 feet high. Call it a concrete bathtub — or an “envelope,” as our tour guide, Chicago Transit Authority Chief Infrastructure Officer Chris Bushell, put it — with rows of support pillars receding into the dim far distance. And all completely unlit, except for some temporary light strung up on the mezzanine and the portable lights we brought along…

The money needed for express train service, likely in the billions, never was obtained. And any private-sector interest melted away when the economy entered its worst downturn in many decades in the late 2000s. So, the city stopped after completing the shell and built no more.

By that time, though, City Hall had spent $218 million — $171 million of CTA bonds, $42 million in tax-increment financing and $5 million from outside grants, the CTA says. And to make the station useable — to connect the tracks, build the escalators, attach all of the needed electrical and plumbing to the outlets — will take an additional $150 million or so, the CTA says.

It’s too bad the city won’t say what they envision doing with this space. Just how long will it stay empty? Because of this, I’m a little surprised Chicago was willing to show reporters exactly what they built. Not only was several hundred million spent, the city still does not have any faster train service to the airports. All together, this is not exactly a shining moment in Chicago infrastructure.