said by BGB:
There is technology that exists that can read plates and tell you if there is an issue. That's one way certain states knows which cars owe outstanding parking tickets so they can boot them. It's also the way the 407 tells if you enter their toll road.
The 407's APNR is a bit different than what they use for vehicles on the road, but either way its not cheap. Peel Regional has a few cars equipped with it, so does Buffalo. A few cars is one thing. Equipping *every* car with something that costs a lot of money to buy is another.