Electric power is the rate at which electrical energy is transferred by an electric circuit.The SI unit of power is the watt, one joule per second. Electric power is usually produced by electric generators, but can also be supplied by sources such as electric batteries. It is usually supplied to businesses and homes by the electric power industry through an electric power grid. Electric power is usually sold by the kilowatt hour (3.6 MJ) which is the product of power in kilowatts multiplied by running time in hours. Electric utilities measure power using an electricity meter, which keeps a running total of the electric energy delivered to a customer. Electrical power provides a low entropy form of energy and can be converted into motion or other forms of energy with high efficiency Źródło: https://en.wikipedia.org/wiki/Electric_power
Then it is necessary to help electricians to solve problems, and control traffic can be much more difficult than the use of traffic lights.
Electricity can make the traffic jams formed especially in large cities are less burdensome for enjoying the busy streets of people.However, you need time to time to monitor these intelligent systems to ensure their trouble-free operation..