Pay By Plate allows you to use Illinois tollways without having a IPass transponder (or any transponder), or even an account.
The mechanics: open a Pay By Plate account and your account is charged whenever you go through an open road toll facility. A picture of your license plate is taken as you go through.
Pay by plate makes sense for people who rarerly use the tollway system and or people who are not comfortable with transponder technology.
This is what happens when you drive on an Illinois Tollway
without a transponder or an account.
When you do this, the Pay by Plate system sends an invoice to the registered owner of the vehicle based on pictures of your license plate.
Any vehicle that goes through an open road tolling facility without a properly functioning transponder will have an image taken of it's license plate. If the plate is not registered to an account then an invoice will be sent to the registered owner of the vehicle.
Pay By Plate will always be more expensive and less reliable than using the electronic IPass device. The Pay By Plate system needs to optically read your license plate, potentially in bad weather, during day or night, license plates may be dirty, and your car may be travelling slow or fast. But Pay By Plate does make sense in some situations.