U+1F6A5 Horizontal Traffic Light

The Wikipedia has the following information about this codepoint:

Traffic lights, traffic signals, or stoplights – also known as robots in South Africa Zambia and Namibia – are signaling devices positioned at road intersections, pedestrian crossings, and other locations in order to control the flow of traffic.

Traffic lights normally consist of three signals, transmitting meaningful information to road users through colours and symbols, including arrows and bicycles. The regular traffic light colours are red, yellow (also known as amber), and green arranged vertically or horizontally in that order. Although this is internationally standardised, variations in traffic light sequences and laws exist on national and local scales.

Traffic lights were first introduced in December 1868 on Parliament Square in London to reduce the need for police officers to control traffic. Since then, electricity and computerised control has advanced traffic light technology and increased intersection capacity. The system is also used for other purposes, including the control of pedestrian movements, variable lane control (such as tidal flow systems or smart motorways), and railway level crossings.