In the USA there is no country-wide policy on this. Each state's transportation department gets to set a policy as to how they perform such roadwork or respond to emergency scenes. This is not a catch-all solution. As others have mentioned, some states will have a police car following behind a slow moving work truck, or just another work truck with a lighted arrow telling you to move one lane over. Unfortunately, Tesla Autopilot currently does not understand police lights or construction signs, so neither will prevent such an accident.
Unfortunately the current Autopilot is not designed to handle these kinds of situations. Until Autopilot 2 becomes more capable, the only way to prevent these kinds of accidents is to be paying attention.
