Defendant violated statute w/o an excuse (prima facie case for breach) and statute must be relevant to the resulting harm: Plaintiff was a member of the class statute meant to protect, Harm suffered. EXCEPTIONS: (negligence per se doesn't apply to kids) Incapacity, No knowledge nor should have known of noncompliance, Inability after reasonable diligence to comply, Emergency not of defendant's own making, Compliance would be more dangerous, Reasonableness under all circumstances (minority not relevant)