The easiest route for out-of-towners is I-90 East. But before you can get driving, you have to get your rental car. All O'Hare rental cars are located at the airport's Multi-Modal Facility, which you reach via a shuttle. From the facility, it's nearly a straight shot into downtown Chicago. The facility is on Mannheim Road, which you can follow straight onto I-190E, which turns into I-90 East. You follow the interstate highway for about 20 minutes, or 15 miles, (on a good day) and then take the 50B Exit, which turns into West Ohio Street.

West Ohio Street takes drivers right into the heart of Chicago, including The Loop and Magnificent Mile.