Two mathematical formula exist which each calculate the Distance To Brake To Stop and Time To Brake To Stop enabling 'Insurers' and an injured third party to -

i)          determine if a negligent road cyclist had broken Proposed New Road Rules intended to reduce Avoidable Trauma Bicycle Accidents; and

ii)         provide more certainty

Two Distance To Brake To Stop Formulae explains the 1st Distance To Brake To Stop Formula and the 2nd Distance To Brake To Stop Formula which each accurately calculate the same Distance To Brake To Stop and Time To Brake To Stop.

The 2nd Distance To Brake To Stop Formula  is sourced from Sight Distance - pg 40 of 'Guide for development of bicycle facilities" known as AASHTO’s “Green Book,”A Policy on Geometric Design of Highways and Streets which incidentally the Russians have plagiarised the "Green Book" with РУКОВОДСТВО ПО РАЗВИТИЮ ВЕЛОДОРОЖЕК AASHTO (США) .  Or perhaps the American Association of State Highway and Transportation Officials sanctioned the Russian copy.

The formula for metric conversions is repeated hereunder.