The authorities in Milan , Italy are using their grey matter, more than most politicians in Europe. Many big cities have started a congestion charge, the biggest and boldest is London, UK, charging you money so that you can come to their city and spend (or maybe earn) money.
Authorities around Europe cite pollution, traffic jams and many other reasons for the tax, and almost all charge anyone money to drive into their city, including motorcycles and scooters. It doesn't matter that PTW generate less traffic, and during the trip, generate less pollution. They still have to pay....more