We already have autonomous self driving solution to that here. It uses all-electric vehicles and they even have a convoy mode where each car follows the lead v

We already have autonomous self driving solution to that here. It uses all-electric vehicles and they even have a convoy mode where each car follows the lead vehicle closely to maximize the number of passengers and minimize wind resistance. The guidance system is pretty primitive - it's all done in hardware with steel wheels on steel rails - but it makes it relatively difficult for it to go off-the-rails.