Have the 18 wheelers burn natural gas

That's T. Boone Pickens plan, as reported in Forbes.
It makes a certain amount of sense. Natural gas tanks are huge compared to gas tanks. The big 18 wheeler tractors have plenty of space for the bulky tankage. Much easier than fitting a natural gas tank into a Corolla.
The writer estimates that converting the truck's diesel engine to natural gas would cost $60,000 a truck. That's damn high. I bought an entire new V8 engine for $3000 a few years ago. Then he thinks the government should pay for the conversion.
Apparently the conversion to natural gas amounts to converting the diesel to a spark ignition engine, and reducing the compression ratio from 18:1 down to 10:1. That's gonna cost you fuel economy, big time. I'd want to see some test results showing fuel consumption on the natural gas converted engine. Would the converted mill be more economical than stock diesel? At what prices for natural gas and for diesel fuel?
And, the chicken and the egg problem. Truck stops don't supply natural gas right now. They won't until there are some customers for the stuff. Truckers won't convert until there is a refueling infrastructure to keep 'em running.