Originally Posted by
TribalistMeathead
I'd research tolls along that route, compare the I-PASS/EZ-PASS rates to the non-I-PASS/EZ-PASS rates, determine how much it would cost to rent a transponder from the rental car company, and see how significantly the cost of the transponder is offset by the savings on tolls. I don't trust a rental car company to not sock me with a fine for driving through a toll plaza without paying, even if I paid the toll online, plus I'm not sure if you get the I-PASS rate if you do that.
I live in Chicago, but when I've rented a car anywhere else, it comes with the toll transponder. I assume the same at ORD, but the OP can just check to make sure. I've never been charged extra for this...but in Chicago the savings is significant.
Arriving at 11 pm, I'd definitely drive on 90 through the city and then on the skyway. It's possible to hit traffic at any time of day here, but almost certainly will be faster than 294 at that time.