From Chicago's NBC 5.
http://www.nbcchicago.com/traffic/transit/How_Do_They_Reverse_The_Express__Lanes_On_The_Kennedy_Expressway__Chicago-112044559.html
Very nice; it ends the wondering of what the odd structure at the west end of the I-70 Reversible Lanes around St. Louis is:
http://maps.google.com/maps?hl=en&ie=UTF8&ll=38.687867,-90.249829&spn=0.001447,0.003433&t=k&z=19&layer=c&cbll=38.687917,-90.249944&panoid=-Y7X9Au2PmEtSy2bBDkqGg&cbp=12,110.49,,0,-1.68 (http://maps.google.com/maps?hl=en&ie=UTF8&ll=38.687867,-90.249829&spn=0.001447,0.003433&t=k&z=19&layer=c&cbll=38.687917,-90.249944&panoid=-Y7X9Au2PmEtSy2bBDkqGg&cbp=12,110.49,,0,-1.68)