Alternative Vehicle Marking Options
While I'm not a fan, the Australian MOS 139 does permit the marking of vehicle operating on the manoeuvring area with a flag. I haven't seen one in the wild but this video caught my eye the other night.
Still not sure what the flag adds to the conspicuity of a large yellow bulldozer but, at least they are compliant ;). Providing, of course, that their aerodrome manual permits it.