Natural gas vehicles (NGVs) have been available to varying degrees since the 1970s, and earlier in some parts of the world. Despite this long history, adoption varies significantly from region to region, with NGVs used mainly for commercial vehicles in North America and parts of Western Europe and for consumer markets in parts of Asia and the Middle East. The primary growth drivers in these countries are the favorable economics of natural gas, the reduction of oil imports, the environmental benefits of lowe