25m at 50km/h is an over-conservative approximation peddled by driving test authorities who assume 1.5 seconds of reaction time. With instantaneous reaction ti

25m at 50km/h is an over-conservative approximation peddled by driving test authorities who assume 1.5 seconds of reaction time. With instantaneous reaction time, the actual braking distance is around 10m unless you jump in front of an escalade or a land rover...