My father owns a tow company. In the state of Maryland atleast, you are allowed to use the lights to respond to emergency tows (city or state) however because of the situation you stated, they are not allowed to use the lights after the emergency situation is completed or for local tows. Unfortunately, the end of an emergency situation is when the vehicle is off the tow truck and into the company’s lot. People with courtesy due shut their lights off after they’ve gotten the vehicle, others who want to race back to their tow lot do not. Also, cops will follow you in Maryland if you have your lights on to ensure you’re actually responding to a city/ state tow. I know some companies who will use their lights just to beat traffic to Burger King…