The worst taxis in Europe are in Rome
Italian Automobile Club (ACI) made rating of best and worst taxis in European cities. It was based on its cost and level of service.
The best taxis in Europe are in Lisbon, Munich, Barcelona, Cologne, Milan, Paris and Berlin.
The worst taxis are in Rome, Madrid, Prague, Luxembourg, Vienna and Amsterdam.
There are 22 cities in complete list. As ACI mentioned, taxi in Rome is very expensive and the price of it does not correspond to its service. In researchers opinion, taxi in the capital of Italy shouldn't cost more than € 50 for a ride, but sometimes it does, and for another thing, taxi drivers in Rome practically don't speak English.