Final answer:
Security guards do not have the authority to enforce highway traffic acts; this is typically the jurisdiction of state or local police. The statement that security guards can enforce such laws on private property is false.
Step-by-step explanation:
The statement that security guards are allowed to enforce the highway traffic act on private property only is False. Security guards have limited powers compared to police officers and generally do not have the authority to enforce traffic laws, which are the purview of state police and local or county police within their jurisdictions. State police have the authority to enforce statewide laws and this includes traffic regulations on highways. Local or county police have a jurisdiction confined to their town or county. Therefore, unless given specific powers under certain conditions, security guards are not typically permitted to enforce the Highway Traffic Act on any property.