Traffic lights are a key factor for a smooth traffic flow. In the future, traffic lights with pedestrian recognition and a holistically interconnected traffic light system will help to make traffic smoother and more efficient in Vienna. Additionally, through weather and environmental sensors that are mounted to Viennese traffic lights, a dense grid of measuring stations is formed, which provide valuable data for diverse applications.
After a comprehensive and successful test phase, a broader roll-out the traffic lights, which independently recognise a pedestrian’s desire to cross, is now possible. Since May 2017, the system has been tested at an unknown intersection in Vienna’s tenth district. This ensured that pedestrians behaved naturally and that the results were not intentionally falsified. As of September 2019, the intelligent traffic lights will gradually replace the approximately 200 existing push-button traffic lights.
Algorithms recognise desire to cross
The system developed by the TU Graz and the municipal department 33 (Public Lighting) differs significantly from a simple motion sensor. While such a system would switch to green even when any other object would pass it, the traffic light camera detects not only people but also whether there is a desire to cross or not. “This system can detect if a person actually wants to cross the road or if he/she has actually nothing to do with the traffic light,” says Walter Mimmler from the municipal department 33. The new traffic lights have the purpose of reducing unnecessarily long waiting times and thus improve the comfort of pedestrians.
The technical installations are used exclusively for detecting the movement patterns and can not be used for personal monitoring. It should also be noted that all data is processed on site and then deleted immediately.
Interconnected traffic lights
In addition to traffic lights with pedestrian recognition, there are also efforts in the City of Vienna to make the traffic light system as a whole smarter and more flexible. This is to be achieved by interconnecting all traffic lights. This allows individual traffic lights to communicate with each other and to resolve unpredictable traffic jams caused by accidents or construction sites quicker. Traffic light phases can thus adapt to the actual traffic situation, thereby improving the traffic flow and reducing emissions.
Integration in navigation systems
The traffic lights should not only communicate with each other, but also pass on valuable traffic-related information to smartphones and navigation devices. With this information, these could in turn calculate at what speed a car has to move around in order to having to stop at red traffic lights as rarely as possible. Corresponding street signs along certain routes could also specify the pace for the green wave. “With this traffic light we would for example have the opportunity to create a green wave at 40 km/h in order to naturally avoid congestion. That’s what a modern metropolis like Vienna needs. I think this is a good investment in our future,” says Maria Vassilakou, Executive City Councillor for Traffic & Transport.
Weather and environmental sensors
In cooperation with the Central Institute for Meteorology and Geodynamics (ZAMG), the traffic lights in Vienna will be equipped with around 10,000 weather and environmental sensors over the next few years. This enables a multitude of applications using “big data analytics”. For example, heat islands can be detected or air quality can be improved through intelligent traffic flow control. The aim is to equip all traffic lights in Vienna with high-quality sensors that are able to directly transfer the data to an online tool for analysis. In the first expansion stage, sensors for measuring temperature and humidity are planned. At a later stage sensors for nitrogen oxide, sulfur oxide and noise will follow. According to ZAMG the system is sustainable and designed in a way that any kind of sensors can be connected. The measurements will provide enormous amounts of data every day. High-performance computers and methods from artificial intelligence and machine learning will analyse and process this data. Using big data analytics patterns and correlations can be identified and used for practical applications.
Municipal Department 33 – Public Lighting
Website: Municipal Department 33 – Traffic Lights (in German)
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