 Hard as it may be to believe. I do have, my favorite argument actually is to take a five minute walk from my place and there is a bridge over Route 66 and to show people, count the cars in the four toll lanes. Count the cars in the six free lanes. Do you notice the difference? Are you convinced that the toll changed the congestion? Not convinced? Come back 20 more times until you're convinced because it's so clear. How could you deny it?