Street cleaning

Does anyone know the specific roles of each vehicle? Is the 'advance vehicle' just a truck with a sign that says 'Caution! Street Sweeping in Progress' (in Japanese, of course)? Does the water sprinkler truck simply spray water, while the road sweeper collects the slushy debris? And does the dump truck haul away the debris afterward?

based upon experience I expect that the advance truck (pick-up) has loads of flashing orange lights 'clear the road!. the sprayer truck is also a sucky monster for the road pavement, urban the third tuck would be another sucky gulley cleanser (especially in Dai-Fung season), on highways the last colleague will always be a heavy ballasted wagon with a collapsable impact barrier. Road sweeper, would be performed at least 2-3hrs previous.

Thanks, iron man. Did you work for the city or through a contractor? The pay must've been very good, as it's at night. All you need is a license, as you learn on the job what buttons to push or levers to press, right?