As indicated by Sicanius, there may be a difference.
"Dustmen" seems to me to be VERY BE, and based on their dictionary definition,
we'd call them "Garbage men" or "Sanitation Engineers"

)) in AE.
"Road sweepers" also seems a bit BE, and probably like our "Street sweepers" who drive around in big things like
this.
Let's wait for the BE experts.