Speed management - A ROAD SAFETY MANUAL FOR DECISION-MAKERS AND PRACTITIONERS https://www.who.int/roadsafety/projects/manuals/speed_manual/en/ https://apps.who.int/iris/bitstream/handle/10665/43915/9782940395040_eng.pdf
it is assumed that all cars in the same area are all same mode.
If the auto brake
The car may go 57m before it stops.
It is assumed high way only safety mode
Some area include different mode cars.
https://www.npa.go.jp/koutsuu/kikaku/regulation_wg/teigen/siryou2.pdf