Locomation, pursuing an autonomous two-truck convoy approach while others are working on equipping one truck for self-driving, claims an environmental impact study shows double-digit improvements in fuel consumption and total operating costs for moving freight by truck.
The electronically tethered trucks will start out with human drivers in both trucks, but only the lead truck will have a driver in control. The following truck will operate as a robot, allowing the driver to work on other tasks...
https://www.freightwaves.com/news/locomation-claims-huge-improvements-in-emissions-and-fuel-savings