Va. Code § 46.2-1119
No axle-like device, commonly called a "tow dolly," used to support the front or rear wheels of a passenger vehicle or pick-up or panel truck for towing purposes, and no axle-like device, commonly called "converter gear," on which is mounted a fifth wheel used to convert a semitrailer to a full trailer, shall be considered vehicles. Either such device, when used on the public highways, shall be equipped with a safety chain or chains of a strength to restrain the device and vehicle being towed, should the connection fail. In addition, either device, when moved on the public highway, shall be equipped with rear marker lights or reflectors when towed without a load. When a tow dolly or converter gear is used to tow a vehicle, the towed vehicle must comply with all requirements of law pertaining to towed vehicles.
Va. Code § 46.2-1119