 Many of the major cities in the world are adding hybrid taxis to their taxicab fleets, led by San Francisco and New York City.By 2009 15% of New York's 13,237 taxis in service are hybrids, the most in any city in North America, and also began retiring its original hybrid fleet after per vehicle.Other cities where taxi service is available with hybrid vehicles include Tokyo, London, Sydney, Melbourne, and Rome.