This wasn't ALL filmed on the Universal lot. There was actual location shooting in Chicago at the famed intersection of Milwaukee/North Avenue/Damen. Here's a screen cap from Streets of Fire:
This is the Damen Avenue Blue Line el stop, looking North down Damen. This intersection is also seen in Flatliners, when Keifer Sutherland is walking across the street and is surrounded by bicycles before he walks down an alley and gets his ass kicked by his karma (that alley is also in the Kevin Bacon movie Stir of Echoes, making this an alley with a Bacon number of one; you can see the alley in this shot - there's a break in the sidewalk just past the streetlight/Lily's Cleaners & Shoe Repair - that's the alley).
Also, just across the street from this train station in the screen cap from Streets of Fire is the The Double Door, which in an incarnation under the name 'Main Street USA' was featured prominently in Steven Segal's debut "Above The Law".
This intersection at North/Damen/Milwaukee is also seen in Robin William's Club Paradise, the Belushi/Arnold pairing Red Heat, and in Cusack's High Fidelity.
When you guys do a show in Chicago, I will happily give you a tour.