The U.S. Postal Service has the largest fleet of NGVs in the nation, with 3,000 natural gas delivery trucks, and plans to convert thousands more. Transit authorities and taxi fleets throughout the U.S. have also discovered the benefits of using natural gas. Even Disneyland uses natural gas to fuel many of its boat rides. The Clean Air Act Amendments of 1990 require centrally-fueled fleets of ten or more vehicles in the nation's 22 smoggiest areas to operate on clean alternative fuels, including natural gas. Natural gas emits less carbon monoxide, nitrogen oxides and non- methane hydrocarbons than gasoline, as shown in the graphs below.
Natural gas is lighter than air.
In the event of a leak, it would disperse upward, rather than pooling on the ground. According to the 1995 Directory of NGV Fueling Stations , published by the American Gas Association , there were more than 1,100 NGV fueling stations in operation or under construction in 46 states, with a growth rate of three to four new stations per week. Many fueling stations are accessible to the public and can fill an NGV in about the same amount of time as a gasoline vehicle. Alternatively, fleets which park at a central location can fuel with natural gas overnight. Many gasoline stations provide convenient fueling for NGVs.