Smart traffic light
Smart traffic lights or Smart traffic signals are by definition according to developers of a pilot project in Pittsburgh ‘A new system that combines existing technology with artificial intelligence to create lights that truly think for themselves’. Also known as intelligent traffic lights and advanced traffic lights this system differs to the traditional Traffic light system which are advanced signaling devices positioned at pedestrian crossings, road intersections and other places to control the flow of traffic. They are, in essence, signals that utilize a buried induction coil to sense the presence of signals that adapt to information that is received from a central computer about the position, speed and direction of vehicles. The pilot project in Pittsburgh may be the first step in their production across the United States of America.
The technology for smart traffic signals has been developed by professors and students at Carnegie Mellon University 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 new system combines existing technology with artificial intelligence to create lights that truly think for themselves.
The signals communicate with each other and adapt to changing traffic conditions to reduce the amount of time that cars spend idling. Using fibre 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 26%.
Companies involved in developing smart traffic management systems include BMW and Siemens, 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 impeding 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.
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 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 Country, 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.
Meanwhile, in the United Kingdom, lights that change to red when sensing that an approaching motorist is traveling too fast are being trialled in Swindon 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.
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.