Hybrids electric vehicles (HEVs) have already been used in the NYMTC region for the past decade. HEVs involve increasing the efficiency of gasoline or diesel vehicles. For the NYMTC region, this entails more miles of travel to the gallon and cheaper fuel costs. The Metropolitan Transportation Authority (MTA) and New York City Transit (NYCT) have used hybrid vehicles for a significant amount of their fleet and will add more hybrid vehicles in the near future.