Longer green phase

Traffic lights recognize baby carriages and people with walkers

Viennese traffic lights are now even smarter.

(Bild: Spitzbart Wolfgang/Wolfgang Spitzbart .)

Vienna's smart traffic lights are now even smarter. At least at a junction on Laaer Berg, where a test phase is currently underway. The traffic lights use AI to detect baby carriages and people with limited mobility and can extend the green phase if necessary. 

Since 2018, 21 intelligent traffic lights have been in use in Vienna: they use cameras to detect when pedestrians are approaching the crossing and automatically request the green phase. This reduces the waiting time for pedestrians.

A team led by Horst Possegger from the Institute of Computer Vision and Visualization at Graz University of Technology has now gone one step further. The researchers have improved the system on behalf of MA33 (public lighting). It now also recognizes baby carriages and people with limited mobility. Using cameras and artificial intelligence (AI).

Test region: intersection of Laaer-Berg-Straße and Theodor-Sickel-Gasse.

(Bild: Bartel Gerhard)

Images deleted again in a flash
A test run with four traffic lights has now started at the intersection of Laaer-Berg-Straße and Theodor-Sickel-Gasse. The cameras evaluate an area of around 30 square meters in the waiting area of the signal system. The image data is only processed locally and deleted within 50 milliseconds, according to the company. 

Posseger and his team worked on the development for three years. For data protection reasons, the AI was not "fed" with real images from real road situations. Instead, students at the university campus used different equipment to recreate the situation like actors, the researcher told "Krone". And they did so in a wide variety of weather conditions. Depending on the mobility aid, the hit rate for mobility restrictions was 85 percent and significantly higher. 

If, exceptionally, a mother with a baby or a pensioner with a walking stick is not recognized, this is not a problem. In the "worst" case, the traffic light switches to the standard green phase. Just like for all other pedestrians.