What should drivers exempt from wearing a seat belt for medical reasons always carry?

Drivers who are exempt from wearing a seat belt for medical reasons must carry a doctor's statement at all times. This document serves as official verification of their exemption status and ensures that law enforcement personnel can confirm the legitimacy of their medical condition if needed. Having this statement is crucial, as it protects the driver from potential legal penalties associated with not wearing a seat belt, which is typically required by law.

Other options do not provide valid or sufficient documentation. For instance, a statement from a family member, while possibly supportive, lacks the authority and professional validation that a doctor's statement provides. A police report is irrelevant in this context since it pertains to incidents rather than medical exemptions. An insurance document also does not address the specific need for medical validation regarding seat belt laws.