Smart traffic lights or Intelligent traffic lights are a

vehicle A vehicle (from la, vehiculum) is a machine that transports people or cargo. Vehicles include wagons, bicycles, motor vehicles (motorcycles, cars, trucks, buses, mobility scooters for disabled people), railed vehicles (trains, trams), ...

traffic Traffic comprises pedestrians, vehicles, ridden or herded animals, trains, and other conveyances that use public ways (roads) for travel and transportation. Traffic laws govern and regulate traffic, while rules of the road include traffic ...

control Control may refer to: Basic meanings Economics and business * Control (management), an element of management * Control, an element of management accounting * Comptroller (or controller), a senior financial officer in an organization * Controlli ...

system that combines traditional

traffic lights Traffic lights, traffic signals, or stoplights – known also as robots in South Africa are signalling devices positioned at intersection (road), road intersections, pedestrian crossings, and other locations in order to control flows of traf ...

with an array of sensors and

artificial intelligence Artificial intelligence (AI) is intelligence—perceiving, synthesizing, and inferring information—demonstrated by machines, as opposed to intelligence displayed by animals and humans. Example tasks in which this is done include speech ...

to intelligently route vehicle and

pedestrian A pedestrian is a person traveling on foot, whether walking or running. In modern times, the term usually refers to someone walking on a road or pavement, but this was not the case historically. The meaning of pedestrian is displayed with ...

traffic. They can form part of a bigger intelligent transport system.

Research

A technology for smart traffic signals has been developed at

Carnegie Mellon University Carnegie Mellon University (CMU) is a private research university in Pittsburgh, Pennsylvania. One of its predecessors was established in 1900 by Andrew Carnegie as the Carnegie Technical Schools; it became the Carnegie Institute of Technology ...

and is being used in a pilot project in Pittsburgh in an effort to reduce vehicle emissions in the city. Unlike other dynamic control signals that adjust the timing and phasing of lights according to limits that are set in controller programming, this system combines existing technology with artificial intelligence. The signals communicate with each other and adapt to changing traffic conditions to reduce the amount of time that cars spend idling. Using fiber optic video receivers similar to those already employed in dynamic control systems, the new technology monitors vehicle numbers and makes changes in real time to avoid congestion wherever possible. Initial results from the pilot study are encouraging: the amount of time that motorists spent idling at lights was reduced by 40% and travel times across the city were reduced by 25%.

Possible benefits

Companies involved in developing smart traffic management systems include BMW and

Siemens Siemens AG ( ) is a German multinational conglomerate corporation and the largest industrial manufacturing company in Europe headquartered in Munich with branch offices abroad. The principal divisions of the corporation are ''Industry'', ''E ...

, who unveiled their system of networked lights in 2010. This system works with the anti-idling technology that many cars are equipped with, to warn them of impending light changes. This should help cars that feature anti-idling systems to use them more intelligently, and the information that networks receive from the cars should help them to adjust light cycling times to make them more efficient. A new patent appearing March 1, 2016 by John F. Hart Jr. is for a "Smart" traffic control system that "sees" traffic approaching the intersections and reacts according to what is needed to keep the flow of vehicles at the most efficient rate. By anticipating the needs of the approaching vehicles, as opposed to reacting to them after they arrive and stop, this system has the potential to save motorist time while cutting down harmful emissions. Romanian and US research teams believe that the time spent by motorists waiting for lights to change could be reduced by over 28% with the introduction of smart traffic lights, and that CO₂ emissions could be cut by as much as 6.5%. A major use of Smart traffic lights could be as part of public transport systems. The signals can be set up to sense the approach of buses or trams and change the signals in their favour, thus improving the speed and efficiency of

sustainable transport Sustainable transport refers to ways of transportation that are sustainable in terms of their social and environmental impacts. Components for evaluating sustainability include the particular vehicles used for road, water or air transport; th ...

modes.

Obstacles to widespread introduction

The main stumbling block to the widespread introduction of such systems is the fact that most vehicles on the road are unable to communicate with the computer systems that town and city authorities use to control traffic lights. However, the trial in Harris County, Texas, referred to above, uses a simple system based on signals received from drivers' cell phones, and it has found that even if only a few drivers have their phone switched on, the system is still able to produce reliable data on traffic density. This means that the adoption of smart traffic lights around the world could be started as soon as a reasonable minority of vehicles were fitted with the technology to communicate with the computers that control the signals, rather than having to wait until the majority of cars had such technology.

The first experiment

In July 2019 the first experiment of a traffic signal regulated by 100% "connected" vehicles was carried on at University of Calabria (Unical) with the help of common commercial smart phones by a team of researchers working for Unical and the innovative Start Up SOMOS.

Simpler systems

In the United Kingdom, lights that changed to red when sensing that an approaching motorist was traveling too fast were being trialled in Swindon in 2011, to see if they are more effective at reducing the number of accidents on the road than the speed cameras that preceded them and which were removed following a council decision in 2008. These lights are more focused on encouraging motorists to obey the law but if they prove to be a success then they could pave the way for more sophisticated systems to be introduced in the UK.

Previous research

In addition to the findings of the Romanian and US researchers mentioned above, scientists in Dresden, Germany came to the conclusion that smart traffic lights could handle their task more efficiently without human interface.

References

{{reflist, refs= {{cite web , url=http://www.mccain-inc.com/news/industry-news/its-solutions/769-smart-traffic-signals-cut-air-pollution-in-pittsburgh.html , title='Smart' traffic signals cut air pollution in Pittsburgh , date=September 25, 2012 , publisher=McCain, Inc. , access-date=September 28, 2012 , archive-url=https://web.archive.org/web/20131010211917/http://www.mccain-inc.com/news/industry-news/its-solutions/769-smart-traffic-signals-cut-air-pollution-in-pittsburgh.html , archive-date=October 10, 2013 {{cite web , url=https://www.treehugger.com/cars/networked-traffic-lights-could-save-time-fuel-and-lives.html , title=Networked Traffic Lights Could Save Time, Fuel, and Lives , date=March 18, 2010 , author=Michael Graham Richard , publisher=Narrative Content Group , access-date=October 21, 2011 {{cite web , url=https://www.newscientist.com/article/dn13306-could-smart-traffic-lights-stop-motorists-fuming/ , title=Could smart traffic lights stop motorists fuming? , date=February 12, 2008 , author=Max Glaskin , access-date=October 21, 2011 {{Cite news , url=https://www.telegraph.co.uk/motoring/news/8521769/Smart-traffic-lights-to-stop-speeders.html , title=Smart traffic lights to stop speeders , last=Millward , first=David , date=May 19, 2011 , newspaper=

The Telegraph ''The Telegraph'', ''Daily Telegraph'', ''Sunday Telegraph'' and other variant names are popular names for newspapers. Newspapers with these titles include: Australia * ''The Telegraph'' (Adelaide), a newspaper in Adelaide, South Australia, publ ...

, language=en-UK {{cite web , url=https://smarteconomy.typepad.com/smart_economy/2008/08/self-organizing.html , title=Self organizing smart traffic lights offer significant reductions in waiting times and fuel consumption , date=August 20, 2008 , access-date=October 21, 2011 Smart devices Traffic signals