It's meant for College Visits with a parent and child, but anybody can use it.
Code is H568 and must be entered at the time of purchase online. There are blackout dates, and you have to travel on at least one week day.
Anyone else trying to get to Decomp festivities can try it. Not sure if it's a national code or not, YMMV!
Now, on another note, anybody on here who will be in Chitown for the Decomp Block Party, post me a reply and lets at least meet up to say hello. I'm also in contact with some local people to volunteer, so I'll be around.