the mercedes trucks used OPTICAL sensors to follow the dotted road line... they had a radar distance finder to figure out the distance to the next vehicle, so that each truck in teh convoy follows 3 feet apart, (more aerodynamic) and the only driver imput required is the front trucker has to stay away in case animals run out, or possibly because a stealth car is in the way?
the trucks would pay for themselves over convetional trucks eventually because of saved fuel costs, they were shown to be much cheaper per lb of cargo being transported, and the loads they could haul were much larger with 100ft trailers instead of 52...
buuut, the 100 ft trailers would require hubs outside of major cities and be restricted to highway use, and the buy in cost for the system with hubs was just too high for any companies so the idea went back to the history books.
mercedes does make trucks though btw, only not for sale in USA... if you watch speedvision late at night tho sometimes you can catch the semi truck racing series.
