How do smart traffic lights work?


How do smart traffic lights work?

  • Smart traffic lights adjust the timing of red and green lights, as well as “walk” and “don’t walk” signs to more efficiently regulate the flow of traffic and pedestrians through an intersection.

  • Smart traffic lights use data from sensors, cameras, GPS, vehicles, cell phones and other devices to detect patterns of traffic and the volume of vehicles, pedestrians and bicyclists approaching an intersection.

  • By dynamically responding to real-time conditions, smart traffic lights can help move traffic through the city more efficiently to reduce commute times, reduce congestion, minimize carbon emissions and improve safety for drivers, pedestrians and bicyclists.

Smart traffic lights are quickly growing in popularity as urban traffic conditions continue to worsen. Fast population growth and an influx of vehicles and pedestrian traffic have resulted in a steady rise of travel times and congestion as well as a greater number of accidents. Smart traffic lights can help to alleviate these problems by more efficiently moving traffic through intersections. But exactly how do smart traffic lights work, and what are the benefits that they offer to cities and citizens? This short introduction, “How do smart traffic lights work?”, is designed to provide a brief overview of this topic.

How do smart traffic lights work?

Smart traffic lights are one of many smart city initiatives that use advanced technology to improve the management of city services and the quality of life for citizens. Along with smart street lights and smart parking technology, smart traffic lights are helping to create a more intelligent traffic management system that enables smart cities to reduce congestion and travel times, to improve safety and to reduce carbon emissions.

Smart traffic lights use a variety of technologies to dynamically change traffic signals at intersections in response to real-time traffic patterns and weather conditions. Technology used by smart traffic lights may include:

  • Sensors and cameras that detect volume and velocity of approaching traffic.

  • Devices embedded in vehicles that communicate with traffic lights at intersections as vehicles approaches.

  • GPS technology in cell phones that helps smart traffic lights detect and monitor approaching vehicles, bicyclists and pedestrians.

  • Sensors that detect weather conditions and air quality.

How do smart traffic lights work to reduce traffic?

Smart traffic lights react to changing traffic patterns in real time, adjusting the length of green lights or red lights at intersections to move traffic more efficiently throughout the city. Smart traffic lights can give priority to buses and streetcars, encouraging citizens to use public transportation that helps reduce vehicle congestion.

How do smart traffic lights work to protect pedestrians?

Smart traffic lights can sense the presence of pedestrians and bicyclists, alerting drivers to their presence and/or stopping traffic to allow time to cross an intersection. Smart traffic lights may also track the progress of a pedestrian or wheelchairs as they cross an intersection, holding the light for an extra period of time when someone needs more time to cross.

How do smart traffic lights work to support emergency response vehicles?

Smart traffic lights enable emergency response vehicles to arrive more quickly at a destination by dynamically changing traffic signals to keep traffic flowing on the route to the emergency and by blocking cars from entering certain intersections before first responders have passed through.

How do smart traffic lights work to limit carbon emissions?

Smart traffic lights help lesson carbon emissions by reducing the amount of time cars must spent idling at red lights. Idling cars are a significant source of greenhouse emissions, generating as much as 30 million tons of carbon dioxide each year, according to the U.S. Department of Energy.

How do smart traffic lights work to improve roadway safety?

Smart traffic lights can help to increase safety on city streets by reducing driver frustration that can lead to distracted or aggressive driving, by adapting signaling to accommodate difficult weather conditions, and by better managing the flow of vehicles, pedestrians and bicycles through intersections.

How do smart traffic lights work with help from Spectrum Enterprise?

Spectrum Enterprise provides a two-way, fully interactive digital network that serves as the connectivity foundation for smart city and smart street initiatives. Spectrum offers symmetrical Internet speeds of up to 100 Gbps that provide cities with the speed and bandwidth they require to transmit and process vast amounts of sensor data. Spectrum also offers gigabit connections for homes and businesses, thousands of WiFi hotspots that will soon be capable of wireless speeds of 1 Gbps, and one of the nation’s largest LTE cellular networks.

Learn more about Spectrum Smart Cities at