As used in this chapter, the following words and terms shall have the following meaning unless the context clearly indicates otherwise: “Certified escort vehicle driver” means a person 18 years of age or older who holds a valid driver’s license and a valid escort vehicle driver certificate issued (i) by the Commonwealth or (ii) by a state whose escort vehicle driver certification program has been determined to be substantially similar to the Commonwealth’s and to which the Commonwealth has extended reciprocity. “Escort vehicle driver certificate” means a credential issued under the laws of the Commonwealth or other state authorizing the holder to escort a permitted vehicle or vehicles. “Permitted vehicle or vehicles” means any vehicle being operated under the provisions of a valid highway hauling permit issued pursuant to § 46.2-1139 that requires that the permitted vehicle or vehicles be accompanied by a certified escort vehicle driver or drivers.