The men who show up at accidents with their flashing truck lights, reflective vests and flags to do the job of keeping traffic moving are for the most part not helpful. Not because they can't be helpful if common sense is used, but some (not all) of these older guys couldn't clear a parking lot with multiple exits. Unfortunately, I have been stopped at far too many accidents where guys show up and, while willing to help with the best of intentions, their decisions often make the traffic situation worse. A job done badly doesn't help. Leave the traffic control to the police and fire on the scene.