I hope this is the correct place for this type of question.
I was wondering what the symbol on a US DOT W21-1a Worker Ahead road sign is.
My wife thinks it's a flagger with their flag down. I think it's a person digging.
Unfortunately, even though I can find everything else, including the dimensions of the image, I can't locate a description of what the image is supposed to be doing.
This is the image for reference:
Official source please, if possible.