Interest in natural gas vehicles soared in the 1990s and then faded. Twenty years later, the cost of gasoline is going up while the cost of natural gas is going down. And that difference in price explains the resurgent interest in natural gas vehicles.
In Indiana, Fair Oaks Dairy Farm does more than just produce milk — it is also in the transportation business. The farm owns 60 trucks, which deliver milk to a processor halfway across the state. Last September, most of the trucks were converted to natural gas.