You joke, but I've heard more than one argument about how self-driving cars will drastically improve traffic because, for inter-city travel, they will be able to drive very close together on the highway in a long convoy, leaving almost no space between cars...
I don't think it's such a bad idea, actually. There's value in having something that can drive in a "train", but that can also disconnect when needed and drive on its own.
If you're driving long distance, you get the advantages of a train, but door-to-door, with no scheduling conflicts and no egregious stop times. If your destination is 5 minutes away, it's still a car.
Or, you know, you could drive (or bike! or waymo!) to the local train station, which should have <30 min, well-scheduled, predictable headways to major cities, then take a train that goes 150+mph, and then drive (or bike! or waymo!) to your final destination, for _far_ less total energy expenditure.
Every car in a train-caravan is schlepping along its own engine, crumple zones, airbags....and with rubber tires...
You joke, but I've heard more than one argument about how self-driving cars will drastically improve traffic because, for inter-city travel, they will be able to drive very close together on the highway in a long convoy, leaving almost no space between cars...