As a lifelong Chicagoan, I can assure you traffic will be a mess around Soldier Field. If you intend to drive, arrive a bit earlier to tailgate and such. Crack a few brews open and pop in U2 to your cd player and soak in the rest of the atmosphere. To miss the traffic, I would take public transportation - the CTA. It is very reliable and the Red Line stop (Roosevelt) is only a 10-15 minute walk from Soldier Field. $2.25 a ride is worth it compared to the price of whatever the parking fee will be (between $20-50 I'm guessing)
Make sure you arrive in time to see Snow Patrol- I've seen them live once before and they are a great act to see. You won't regret it.
