You misunderstand my argument. I'm saying that in order for automated cars to "decrease traffic" (by your definition), "tighter grouping" is necessary. I'm further saying that with non-automated cars in traffic, the grouping is already maxed as it is. It's a lowest-common-denominator problem - if 80% of your cars are automated and can keep a follow distance of 50 feet at 70mph but 20% are piloted and require a follow distance of 250 feet at 70mph, your fleet pulls a lot closer to the wide spacing than the close. The way it actually gets handled is gonna be interesting to see; it'll depend on a lot of variables. "A to B faster" remains to be seen, and as we're now both saying, dependent on decreased following distance. Decreased following distance is dependent on pilotless saturation. Either way, the mechanism is "more cars with less road" and that's "traffic."