That's an age-old fantasy technology. Today you'd do it with electric buses(/trucks) that run on dedicated highways, or at least on dedicated lanes that are no

That's an age-old fantasy technology. Today you'd do it with electric buses(/trucks) that run on dedicated highways, or at least on dedicated lanes that are not only electrified (bus operates from a pair of pantigraphs except for that "last mile" part of the trip in regular roads or when there is some maintenance situation), but also exclusively run computer controlled in paceline formations. No physical connection (or perhaps physical connection for power crossfeed, to share pantograph wear, but no physical connection for push/pull), just a low latency, ack-heavy data link so that they would all accelerate and brake perfectly synchronized. Those buses (or trucks) would benefit from slipstream just like train cars do, but still be able to independently branch away or join at any exit. Of course the power bill would have to be shared by the whole formation, no need to rotate the lead (like a bicycle paceline would do) except perhaps in an unelectrified segment or during a power outage. This would offer point to point connections, have all the efficiency benefits of trains except for the energy cost of rubber-on-tarmac relative to steel-on-steel, and would also offer greatly increased throughout compared to trains because a formation like that would retain almost all of the emergency breaking capability of trucks (and realistically speaking, have better capability than a queue of human-operated trucks that keep almost but not quite enough safety distance for human reaction). The only reason I see why this is not the obvious future is that it requires enormous critical mass to pick up. It probably needs electric trucks first, then electric trucks with pantograph on some main lines, and only then pantograph electric trucks joining into robotic pacelines at some even later point. (the absolute end game state of course would be dedicated rights of way with a rail option useable to dual mode vehicles that could quickly drop on their road wheels not only for exiting formation but also for braking - note that breaking should not even exist in a formation like that, outside emergencies.