Traffic light course

I MODULE: The history of the traffic light: the first example of signage attributable to today's traffic light dates back to 1868 II MODULE: The sequence of colors: three-time traffic light, four-time traffic light and five-time traffic light III MODULE: The main functions of a traffic light: timing of the various phases of go-ahead and stop to avoid the formation of queues and automated traffic lights controls, also put at the service of public transport to facilitate the transit of surface vehicles. IV MODULE: The traffic light assistance and maintenance service work of the figure of the traffic light: the law n. 186 of 1 March 1968 V MODULE: The maintenance service can be understood as: ordinary maintenance and extraordinary maintenance MODULE VI: The objectives of the maintenance of a traffic light: to increase the longevity of the system,