A Tesla Semi electric truck can tow about 80.000 lbs (pound). That is about 30 car weighs worth. In theory you could load 30 cars onto one Semi and haul it 500 miles or 800 km through Europe, which is about 1/3ths the way to Italy. A single car trailer only has a 5 car capacity, so you could tow about 5 of them behind one Semi, towing 25 cars. They would have baggage aboard of course.
You could use a small cabin right behind the semi as the passenger compartment. This would have to have 100 seats at least. You would get a road train that would stretch for at least 50 meters. But it would be efficient and bring people to their holiday destination with a lot less energy wasted than when they would drive their ICE cars.
It seems we’d need to design special trailers, because many assume to be single trailer situations..
The emissions from trucks are 20% of total emissions, and they are very dirty. It is thus very important to replace those trucks with electric vehicles
So one trailer for people, 5 for cars, regular stops every 3 hours or so, charging near Turin or Switzerland (hydropower?) and arriving in Italy, South of France or Spain safely and rested. Do we still need rail?