As gas prices climb upward, natural gas is abundant and cheap& likely to remain that way. However, because of technological and legal hurdles involved in converting a car to run on natural gas, it can cost thousands of dollars up front.
Photo of exploded CNG tank made from carbon fiber. Safety incidents happen in all kinds of vehicles, including those fuels by compressed natural gas. (From Indianapolis refuse truck fire in Jan. 2015 - photo credit - NGT News and the Indianapolis Fire Dept.).