top view on tipper truck as unloading gravel from a trailer while another is waiting to be unloaded, bulldozer flatting

above base building bulldozer cargo civil construction crawler delivery drive dumper engineering equalizes equates flat flatting fraction gravel industrial industry layer level lifting load logistics lorry manage mechanization out overhead pebble pour push road roadway roadwork site spread spreading stone supply tipper top trailer transport transportation truck trucking two under unload unloading