"Transformers 3" filming will again make it a challenge to travel around the Loop this weekend.
Film crews will be set up on Upper Wacker Drive between Wabash and State throughout the weekend, and Wacker will be closed from 8 pm Friday through 5 am Monday.
A helicopter aerial photography unit will also be flying in the area and special effects and pyrotechnics will be in use, including simulated gunfire, smoke, fireballs and explosions.
For more details on CTA reroutes or all CTA service, visit www.transitchicago.com, or call 1-888-YOUR-CTA (1-888-968-7282).
"Transformers 3" is slated for release next June or July.