Ark. Code Ann. § 27-50-205: Power and authority of division

(a) The Arkansas Highway Police Division of the Arkansas Department of Transportation shall have the power and authority to enforce all laws pertaining to the unlawful operation of motor vehicles over the highways of this state.

(b) This responsibility shall include, but not be limited to, a full responsibility along with the Division of Arkansas State Police and the Arkansas Department of Transportation for enforcement of the Hazardous Materials Transportation Act of 1977, § 27-2-101 et seq., and the rules promulgated thereunder.