I gotta take issue with those numbers. A car moving at 130kph covers 18 meters in about half a second. According to the numbers I found online, experts estimate the perception-reaction time for braking at 1.5 seconds, which is up from the value of 0.75 seconds that they used to use. Thirteen and a half meters is an unrealistically-close following distance, even for German super-humans.

I have not driven on the Autobahn, but the videos I can find show scenes much more consistent with a ~55 meter (1.5 seconds) gap between cars, or much-slower traffic speeds. That drops the estimated human-throughput way, way down.