Chicago is very lucky to have a Blue Line, an inexpensive and dependable transportation service from downtown to O’hare International Airport. Most public transportation to international gateways in other cities are significantly more expensive.
The $2.25 includes a transfer within the CTA system. The trick is that you need to get the ticket within the vending system in the subway machines. The CTA bus will not give you a ticket that is transferable. Otherwise, you will have to pay twice. Once on the Blue Line, you can transfer anywhere with the system. From the Blue Line you can transfer over to the Red Line which run North and South. You can continue on the Blue Line to downtown or the Amtrak station. The map for every station on the Blue Line is particularly informative. Guides for the CTA are particularly good.
For example, in San Francisco, a ride on the BART is $8.10 plus the cost of MUNI from downtown. In New York, it is $2.25 plus $5 for the Airtrain to JFK, and in Washington DC it is $2.15 for the Metro and $10 for the Washington Flyer. The $2.25 from downtown Chicago to O’hare on the Blue Line is a relative bargain.
The Blue Line allows you to bypass all the traffic on I-90 and I-94, which can be pretty bad during rush hour – even before rush hour in Chicago. On Friday and Sunday, traffic to O’hare is are particularly bad, and bumper to bumper traffic will start many exits from O’hare. The Blue Line allows you to pay a flat fee and never worry about how much traffic is going to cost you in extra cab fare. The Blue Line runs very often, especially during rush hour. There is generally cell phone reception in most underground stations in downtown Chicago, and the train is above ground once you leave downtown.
Additionally, the Blue is great if you have to go between airports. You can change airports from O’hare to Midway on the same CTA system for a mere $2.25. That is, you can take the Blue Line to the Clark and Lake Station, and then transfer to the Orange Line to go to Midway. In almost all major cities, this is difficult to do. In San Francisco, you would have to take BART from SFO to Oakland. In Los Angeles, going from LAX to Burbank, you have to take a shuttle. In New York, you could do it, but it takes a very long time on the subway for $9.75, but it take a very long time.