Construction sites are a danger to everyone, including cops who work traffic. Whether thhere are high voltage power lines in play, orrisks of falls or falling objects, they are equally as in risk of danger as any other worker or member of public from a safety and legal point of view.
If the cops are in the vicinity of construction sites, accidents are always possibilities and shouldn't be ruled out. No matter how many safety measures are taken, accidents always happen. The best the cops can do is take precautions and follow instructions from the construction workers about safety and preventative measures.
Construction sites can be dangerous places for traffic cops. The greatest risk to police officers working construction sites would be a vehicle hitting an officer. However, in the wake of recent violence against law enforcement, there would be the potential of attacks against traffic cops too. In short, construction sites may prove to be more dangerous for police officers that work them then previously thought.
Construction sites are another visual cue to distract people while driving. Some are so busy rubbernecking they misinterpret the distance between objects and are unable to drive safely around them, including a police officer directing traffic. It is definitely dangerous for the officers and workers at the site. There's got to be a safer way.