In Thompson v. Sanford, 281 Ark. 365, 663 S.W.2d 932 (1984) the Dardanelle School District was held liable for negligence of its employee who was using a tractor on a highway when it struck a motorcycle. In Thompson, a school-district employee was driving a tractor on a public road, as opposed to school grounds, and injured the plaintiff. The supreme court affirmed the judgment of the trial court based on Sturdivant v. City of Farmington, 255 Ark. 415, 500 S.W.2d 769 (1973), where the supreme court held that a municipality which fails to conform to the insurance requirements would be responsible as a self-insurer for liability not to exceed the minimum amounts set out in the Motor Vehicle Safety Responsibility Act.