I’ve been reading about tests of platooning literally since the 90s. Practically, it’s a recipe for a pileup if there’s a mechanical failure or unexpected event (something falls off a vehicle, etC).

It might work for unmanned trucks, where only the cargo is at risk. Cars with people in them won’t follow that closely. If anything, there will be LESS tailgating, not more — I suspect something like a “braking distance + 50% safety factor” rule will be followed.

You already have vehicles that are heavily automated, like aircraft and metro trains, that COULD theoretically operate much closer. But good engineering dictates safety factors.