Another video explanation of the concept of truck platooning as it is done in the United States can be found at vimeo.com/146972113 The Peloton company uses a similar (perhaps the same?) technology on American highways in 18 states where legislation has been changed to allow truck platooning. Read more at the webpage: www.digitaltrends.com/cars/peloton-technology-lets-semi-trucks-save-fuel-platooning/
As you can see, the video refers to freeways. But also platooning does not mean that they cannot be "broken" allowing a vehicle to sneak into the platoon, so overtaking can be done in multiple steps if necessary (when two-lane highways, again).