The lights are the lights, be they mounted on a restaurant building or a police vehicle. It is the place they have been mounted that creates all the difference and provides them with a contextual significance. When the blue lights mounted on a vehicle, which may or may not be used with the police sirens, are lighted up, they have a specific meaning: This is a police vehicle on an emergency mission. The mission may range from responding to an assistance request to the pursuit of criminals. The police vehicle on active duty is the guardian angel in the modern metropolis. These lights are to the vehicles what badges are to the policemen. They identify the public vehicles and they transmit a very important message to the citizens. The message is a request that it is the duty of each law abiding citizen to be helpful under these circumstances. The help might range from giving way to being just careful because a crime might be in progress close by. Unfortunately, more people die in violent crimes in the world’s biggest 10 cities than the active combatants die in the battlefield; this comparison has been true for more than six decades now.
There is good and there is evil in this world. The rapid urbanization in the aftermath of industrialization has increased the crime rates many fold. One of the major reasons for the urbanization was the employment opportunities created as a resulting of factories being sprung up. Cities expanded alongside the factories and people migrated from the country side to reap the benefits of the opportunities offered by the city life. A byproduct of the cities getting larger was the loss of communal system developed over centuries. People no more knew everyone they interacted with. It became a practical impossibility to create accountability safety nets through social norms alone. The social norms do not work without a credible threat of alienation and since the metropolis was so humongous that no single individual had any real threat of a social boycott, the social contract dissolved in the industrial age.
The increase in violence led to the evolution of modern, systematic, uniformed police forces which had the sole responsibility of upholding the law. The law now was guarded not by the social contract, but through coercive state ability to execute it. As an identity of the state officials who had the authority to execute it, the police forces were given a uniform, a badge and their vehicles were equipped with sirens and blue lights; these lights over time were identified as the universal police exclusive. It is hard to imagine how police force would operationally perform its duties today if it were to be stripped of this identifying trait.