I live about 30 miles or so from ORD, and it consistently takes me 40 mins from my driveway to the employee lot (45 mins going to the terminal or pay parking). I always leave 1h30m before my check-in time, gives me plenty of time to spare. Not sure what airline you work for, but seeing as you mentioned SLC, I'm going to assume SkyWest, like myself. If that is the case, get a SIDA badge from the ORD badging office. Go to the ORD employee lounge (below gate E-3), get an application for a green badge from one of the office people down there), then go to the badging office. This one is tricky....go to Terminal One (United) baggage claim, walk to the far end, go down the escalator, go left, and you should see it. You can always ask someone if you get lost.

Anyway, SkyWest employees park in the United Airlines lot, there is a bus that runs frequently to Terminal One from there.

BTW....if you don't have a SIDA badge for ORD, you will need an escort to the crew lounge, as it is entered from the ramp below E-3