Another Italian tourist site has decided to regulate its hefty traffic – this time the buried city of Pompeii, which is introducing a visitor limit of 20,000. The move follows one by the city of Venice, whose residents have long complained about being overrun by tourists. Earlier in the year it became the first city in the world to charge an entrance fee: €5 ($5.36), which will eventually double. At Pompeii, now an archaeological park in which visitors can learn about the victims of the Vesuvius eruption, tourists flock to the attraction – one of Italy’s most popular – by the hordes. By instit…