I’m thinking it was the decision of trucking company. The companies are looking for an edge on the competition. Lower carbon, environmentally sentinel etc.I was at a truck stop on our way home from Washington yesterday. There were a couple trucks with lowboys and huge farm/industrial tractors without wheels parked beside the place. They were dark blue and I forget the brand. I wish I had the forethought of mind to take a picture. Nevertheless, these tractors had placards on them indicating they ran on compressed natural gas. Why would anyone buy a compressed natural gas tractor over diesel? Future is here it seems. I am NOT saying there won't be ANY use of diesel in the future. Just very little. Just like leaded gasoline, not much being used anymore in this country except for what, old planes?