While in DC, I accidentally went on an EZ-Pass Tollway that required the use of an EZ-Pass. This was I-495. I went to their website https://expresslanes.com/ and setup an email notification in hopes of paying the toll before they charged it to the rental car company. I never received an email.
After a couple weeks, I received a letter in the mail. It looks like the rental car had an EZ-Pass and they (Alamo) were charging me $10 for the privilege of using it. So the toll was only $1.85 and the convenience fee was $10.
At least they didn't charge me $3.95 per day of the rental car.
