Why should we pay cops to watch construction sites?

In Boston we pay our police to sit at construction sites 'for safety". It's complete nonsense. They rarely pay attention to what's going on, they are terrible at directing traffic, they talk on their cell phones all day, socialize with the constuction workers and get paid big bucks in overtime for it. The state police are even worse. All they have to do is sit in their cruisers and sleep. Each trooper gets their own car so it's even more expensive. On any given piece road work being done you'll see at least two cops in cruisers getting paid mive amounts of cash (sometimes many more than that). The only people that hurt at these construction sites are the cops who occasionally get hit by cars. Haha!!