One suggestion from someone who learned the hard way...
Take the time to swing throug an attended booth, at one of your first stations, to make sure the pass is working correctly. I drove ours to and from MI over Memorial Day , flying through the highway-speed checkpoints thinking everything was fine. Two months later, on another trip out, I pulled up to the gate on I90 (where going through the gate is our only option) and, sure enough, nothing! Gate didn't move, and I was stuck with traffic all over the place, no way to go forward, and a 35' trailer in tow. Not fun!
I eventually got through that disaster to a gate attendant to discover that the transponder wasn't working all along, and the had to follow up with written affidavits and other paperwork so that they would waive all of the penalties on the tolls from the first trip.
Really wish I had double-checked it's functionality at the outset!