I'm assuming these people aren't official DoT workers, but a collective of citizens clandestinely installing cycling safety infrastructure. Could be wrong, just my immediate assumption.
yeah I can't imagine someone who does this for a job would carry a claw hammer. or that it would take so many people to bolt down each pylon. like I dunno maybe one or 2 to drill the holes, one to install and bond the studs, one to bolt the pylons down, and a traffic guy in each direction.
The concrete anchors are often ones you tap in first with the hammer to first set them into place. Then, you crank the bolt down, which drives out the anchor into the surrounding material. The hammer is just to get it started and fully down the bore hole.
You might also use it to align the pylon. It's easier to tap the base gently to move it a few cm into place over the holes than to pick the whole pylon up and down while aligning it.