Tennessee Code Title 56. Insurance § 56-7-1109

(a) Whenever a person who is employed as a driver is involved in a traffic accident in the course of employment and while operating a motor vehicle owned by or leased to the person's employer, the accident shall in no way be considered by the person's personal automobile insurance carrier in fixing insurance premiums, nor shall it cause any increase in the person's personal automobile insurance premiums, if the accident did not involve negligence on the part of the person. Likewise, an accident involving the person while using the person's personal vehicle and not involving negligence by the person shall not be considered relative to insurance or premiums for the person's employer.

(b) Whenever a person is involved in a traffic accident while operating a motor vehicle, if the accident did not involve negligence on the part of the person, it shall in no way be considered by the person's personal automobile insurance carrier in fixing premiums, nor shall it cause any increase in the person's personal automobile insurance premiums. Likewise, an accident involving the person, while operating another person's insured vehicle under the other person's authority and not involving negligence on the part of the driver, shall not cause an increase in the personal automobile insurance premiums for the owner of the vehicle; provided, that the owner did not violate any contractual duties or obligations by authorizing the driver to operate the vehicle.