I remember when the I-520 floating bridge stopped taking tolls altogether. The bridge was paid for, so tolls were removed. Can you imagine them doing that today, on ANY toll road?
And now that it costs them basically nothing to charge tolls, I expect to see more and more of this. Especially as more and more electric cars are hitting the road.
Of course, it means they will also track everywhere you drive.
What do you think EZ-Pass is all about?