At a time when, in the West, people drive fewer miles and the number of gasoline and diesel retail stations is on the decrease, Compressed Natural Gas (CNG) is bucking the trend. The original justification for using CNG in transports despite its greater bulk is its low cost, on an energy basis. Oil prices have been largely stable since 2011, but natural gas-powered transportation is continuing its progress on both sides of the Atlantic, largely driven more by environmental considerations. The price differential of CNG-to-gasoline is similar in the US and in Europe on average. Within Europe, this differential is extremely variable from one country to another, and so is the rate of Natural Gas Vehicle (NGV) penetration in each country. Italy has among Europe's most expensive gasoline, and it has the most NGVs in Europe. However, fuel economics are far from being the only factor behind the success of CNG as a fuel. Clean air standards, domestic resource utilization, and in certain developing world countries, fuel subsidy substitution are equally important reasons why CNG has been promoted by governments.