Waze and Spothero are teaming up to put beacons on Lower Wacker Drive that will allow your GPS to finally work. Here's more info from NBC:
"'This Monday, SpotHero, CDOT and Waze started installing over 400 Waze beacons on Lower Wacker Drive and other lower roads where, historically, GPS services lose reception, impeding driver’s ability to navigate to their destination,' Mosbacher said. Chicago has 5 miles of multi-level roads like Lower Wacker, shielded from the satellite signals that provide GPS service."
This is good news if you drive those roads a lot!