If your flying domestically or internationally just know you have several options available to you! You can reserve full service parking online. However, you cannot reserve Economy parking online! Before you arrive at O'Hare figure out where you want to park and then go online and check to see if that lot if open or filled up. The website also has a map for you to use! These parking lots get full fast! Once you figure out where you want to park, grab a ticket and keep it IN YOUR CUP HOLDER in your car so you don't have to worry about carrying it around and losing it during your travels! Once you arrive back from your travels, take the ticket out and go to the exit where you'll find ticket machines. Put your ticket in the machine and THEN put your credit card in the SAME spot! This confused the crap out of me because it doesn't look like a place to put your credit card, but you seriously do put your credit card in the SAME spot as you put your ticket in! It will suck up your card and then after the transaction is complete, it will spit your card back out to you! Also keep in mind, when you figure out where you want to park, just head straight to the corner of the parking lot because you can waste an extra 15 minutes looking for an empty parking spot and you'll have no luck at all! We drove up and down the rows for 15 minutes. If only I'd have known ahead of time!
Parking Lot G
And if you're looking for the cheapest parking lot, this is it! Parking lot G costs only $10/day. It's easy to find. Its the very last parking lot on the left hand side of the street! We spent 15 minutes driving up and down the rows until I seen a shuttle bus coming. I immediately went to the back corner and there was only about 10 parking spots still available! We missed that shuttle, but only had to wait 10 minutes for another one to arrive back to pick us up and bring us to the airport!