The drawbar or other connection between any two vehicles, one of which is towing or drawing the other on a highway, shall not exceed fifteen feet in length from one vehicle to the other, except a vehicle being towed with a connection device that is an integral component of the vehicle and is designed to attach to a lead unit with construction in such a manner as to allow articulation at the attachment point on the chassis of the towed vehicle but not to allow lateral or side-to-side movement. Such connecting device shall meet the safety standards for towbar failure or disconnection in the parts, subparts, and sections of Title 49 of the Code of Federal Regulations adopted pursuant to section 75-363 and shall have displayed at approximately the halfway point between the towing vehicle and the towed vehicle on the connecting mechanism a red flag or other signal or cloth not less than twelve inches both in length and width that shall be at least five feet and not more than ten feet from the level of the paving and shall be displayed along the outside line on both sides of the towing and towed vehicles. Whenever such connection consists of a chain, rope, or cable, there shall be displayed upon such connection a red flag or other signal or cloth not less than twelve inches both in length and width.