An automatic braking assembly and method are provided, where the automated braking assembly is formed as a complete unit, and is configured to be connected with a manually propelled vehicle. The automatic braking assembly that is formed as a complete unit includes (a) a housing, and (b) an automatic braking mechanism supported within the housing. The housing is configured to be connected with a portion of the vehicle to locate the automatic braking assembly in a predetermined position relative to a wheel of the vehicle, such that the automatic braking assembly will lock the wheel against movement when an occupant of the vehicle begins to rise from a seated position in the vehicle.
