(a) As used in this section:

(1) “Charitable organization” means any charitable unit of a religious or civic group exempt from taxation under 26 U.S.C. § 501, including those supported wholly or partially by private donations;

(2) “Human service agency” means any human service unit, clinic, senior citizens program, congregate meal center, or day care center for the elderly, whether supported wholly or partially by public funds;

(3) “Volunteer” means an individual providing volunteer transportation who may receive reimbursement for actual expenses or an allowance to defray expenses of operating the vehicle used to provide transportation services, but does not receive compensation for the person's time; and

(4) “Volunteer transportation” means motor vehicle transportation provided by a volunteer under the direction, sponsorship, or supervision of a human service agency or a charitable organization.

(b) Any volunteer, who provides volunteer transportation for senior citizens through a charitable organization or human service agency, shall not be individually liable for any civil damages above the policy limits collectable from any policy of insurance that would be obligated to make payment on behalf of the volunteer or on behalf of a person or entity that would be vicariously liable for the volunteer's conduct when liability for civil damages is limited by this section for an injury to the senior citizen arising out of or resulting from the transportation if the volunteer was acting in good faith and within the scope of the volunteer's official actions and duties on behalf of the charitable organization or human service agency, unless the volunteer's conduct constitutes gross negligence or willful and wanton misconduct; provided, that the charitable organization or human service agency is liable for damages and maintains liability insurance coverage at least equal to the minimum limits set forth in § 29-20-403 of the Tennessee Governmental Tort Liability Act.