Flashing amber lights are used on construction vehicles, towing vehicles, tow cars that are attending, snow-removal equipment, sanding equipment, pilot cars, and vehicles that are required by permit to use them, such as some oversize vehicles or vehicles carrying oversize loads. If your vehicle is going to haul an oversize load, obtain a Commercial Vehicle Safety & Enforcement permit from ICBC. This will allow you to mount flashing amber or red lights on your vehicle as well as the appropriate oversize signs.