I was little surprised at first about: "three cars behind the truck at an average separation of 6m". But this is probably an idea to lessen drag. It doesn't matter what powers our cars(gasoline, biofuel electricity), less is less, and we need all technology that can do it.

This is probably very important step towards self driving cars. Because some kind of commercial product will bring loads of money to the field, even if it's very basic.