It might not work for other vehicles on the interstate, though. If there's not room to pull in between them, then you have to pass all of them at one time. If you're a semi that wants to drive 1 or 2 MPH faster than them, that's going to be a very long, slow, pass. It will be even worse if it's in hilly country, where the semi attempting to pass may have higher speed on flat ground, but less power for climbing. That could block both lanes for a really long time. Human drivers in cars (some of whom want to drive faster than semis, and have more horsepower per ton at their disposal) will be very annoyed.
Then you get one "train" trying to pass another, and things get even worse.
Then the train gets off the interstate. They hit a traffic light. Less than all of the train makes it through the light in one cycle. Now what?