I am currently designing a 6 axle heavy hauler and am currently working on the required lights. i have found some documents about what color lights are required and where to place them, although I can't seem to find anything which states a size for any of the lights needed. Specifically for the top mounted strobe lights, does anyone use a standard size? Or is generally just a rule of thumb that they can be any size as long as they are visible? If they just have to be visible, is there a brightness amount needed?