Whether they're doing it effectively isn't entirely relevant. That's the goal of the variable pricing system in place here though.
Keep raising the price until enough people are no longer willing to pay that the road isn't congested.
Keep raising the price until enough people are no longer willing to pay that the road isn't congested.
You'd have to prove that to me for this particular instance. Here, you are post hoc rationalizing it and it's much like a circular argument.