In Chicago, it is easy to drive but parking is very expensive especially downtown and there are often traffic jams on the Express ways. Some people choose to own a car for weekends or other occassional needs, but use public transportation to commute to work on a daily basis.
It is possible to live in Chicago without a car as the public transportation network in Chicago proper is very developed and well connected. There is also an efficient train system that links downtown with the Chicago suburbs. Moreover if you need a ride you can also rely on taxis that are numerous or even share a car thanks to companies such as Zipcar or I-Go (See “Renting a Car” for more information).
It is also very easy to go to the airport even if you do not own a car: the Metra blue line connects downtown with The O’Hare international airport. You can also make a reservation with the company Airport Express that will come to pick you up at your home (http://www.airportexpress.com/). O’Hare international Airport is one of the main hubs of the US: from there you can go anywhere in the US and in the world.