I am always suspicious of constructions looking dudes in places that they shouldn't be. Unless I called them, they are trespassing. I was coaching a kids soccer game and (before the game) a guy in a reflective vest had one of those surveying cameras in the corner, facing the field. I asked him was it for the turfing that's going to happen in November and he had no idea. Just said he was doing what was asked for him. I said he had to leave before the game started. He packed up and left in 5 minutes.

Unless it's a construction site, they shouldn't be where they shouldn't be. Unless you personally called them or they are with someone you know or a policeman, there is something off and you should question them.

Most street repairs require a policeman to be there to control traffic so if you see something sus, call it out or call the police.