CHICAGO — Do your grocery shopping Wednesday, South Loopers.
"It'll be an absolute gridlock between Thursday and Sunday," said Tina Feldstein, president of the Prairie District Neighborhood Alliance. "Do all your shopping right now, before Thursday, especially if you need your car."
Drivers coming from north of Soldier Field won't be able to sneak off Lake Shore Drive onto Balbo Drive or Jackson Boulevard.
From Michigan Avenue to Lake Shore Drive, Balbo and Jackson closed Wednesday to set up a medical facility for the marathon on Sunday, said Lily Homstad, marathon spokeswoman.
Grant Park will close completely at 10 a.m. Friday.
All 45,000 marathon runners will also descend on McCormick Place to pick up their race packets Friday and Saturday.
The packets are required to be picked up at the Marathon Health & Fitness Expo, which takes place from 9 a.m. to 8 p.m. Friday and 9 a.m. to 6 p.m. Saturday. The expo is also free and open to the public.