How long will it take me to drive from the Loop to O'Hare on a Wednesday to make a 7:20pm departing flight?

I think you would need AT LEAST three hours if you are going by car.

1. Traffic after 4 pm can be very slow. In the best case, you can get to ORD by car in 35 minutes. If traffic is snarled, or there is an accident, it could take 75-90 mintes to drive.

2. BUT, you need to figure how much time it will take for you to get to your car and then finding parking at the airport and then walking to the terminal. This can easily take 30 minutes in addition to driving time.

3. Do you have to drop off luggage? Figure in the time.

4. Waiting in an airport security line during rush hour can take another 30 minutes.

Have you considered taking the CTA Blue Line to the airport? Total riding time is about 40 minutes.

Leave by 5:00 pm...you'll need about 25 min to park car and catch the ATS to your terminal

I don't know how bad the traffic is gonna be, but right around 30-35 minutes.