They wanted to reduce congestion. Not eliminate traffic. At that time. One can conclude the policy worked at it's time. 20 years later, today is a different d

They wanted to reduce congestion. Not eliminate traffic. At that time. One can conclude the policy worked at it's time. 20 years later, today is a different day. One could say congestion is there today, but they can't say how much further congestion has been avoided. Municipality can decide to reduce (not eliminate) it again today. It is the laffer curve, in 3d (time).