I can't change!

Having to pay $5 or $20 for a one way to the airport because those were the only bills I had to leave town with... was not fun!

Why aren't there any change machines on the system, at least in "The Loop" where they would come in handy for passengers in a rush to catch a train. I wish the vending machines were equipped with change makers or credit cards.

There is a change machine in the loop, it's called Borders book store. Go in, buy a "Trains" or "Road and Track" with your $20. Then, enjoy the ride while using (2) $1 bill notes to pay, and read your new purchase - I do this all the time, as I find myself in a similar predicament. I don't give $20 to the CTA at one time, ever.