....The transportation network flow is a good key index of a country's development reference. Therefore, how to control the traffic becomes a very important task. The simplest way to bring order to the roads is to use traffic signs. It's also beneficial when a traffic accident occurs. The impeccable traffic information systems help both the police and the ambulance in their work of directing the traffic and transferring the casualties.
....Another big task is finding a sustainable electricity supply for the traffic signs or traffic information systems. Obviously, to find an electricity supply in the developed countries is not a problem. However, in the under developed countries where a supply of stable electricity always proves difficult to find, renewable energy sources such as solar or wind power systems is the best solution. They can generate the electricity for the street lights, traffic signs, traffic indicators, emergency phones, solar car chargers, road signs?etc. and solve the traffic related problems without being affected by local power outages.