Traffic-sign recognition

Traffic-sign recognition (TSR) is a technology by which a vehicle is able to recognize the traffic signs put on the road e.g. "speed limit" or "children" or "turn ahead". This is part of the features collectively called ADAS. The technology is being developed by a variety of automotive suppliers. It uses image processing techniques to detect the traffic signs. The detection methods can be generally divided into color based, shape based and learning based methods. The Vienna Convention on Road Signs and Signals is a treaty signed in 1968 which has been able to standardize traffic signs across different countries. About 52 countries have signed this treaty, which includes 31 countries from Europe. The convention has broadly classified the road signs into seven categories designated with letters A to H. This standardization has been the main drive for helping the development of traffic-sign recognition systems that can be used globally. Traffic-sign recognition first appeared, in the form of speed limit sign recognition, in 2008 for the 2009 Vauxhall Insignia. Later in 2009 they appeared on the new BMW 7 Series, and the following year on the Mercedes-Benz S-Class. At that time, these systems only detected the round speed limit signs found all across Europe (e.g.). Second-generation systems can also detect overtaking restrictions. It was introduced in 2008 in the Opel Insignia, later followed by the Opel Astra and the Saab 9-5. This technology is also available on the 2011 Volkswagen Phaeton and, since 2012, in the Volvo S80, V70, XC70, XC60, S60, V60 and V40, as a technology called Road Sign Information. They are not able to recognize city limit signs, which in most European countries are associated with speed limits, as they are too similar to direction signs. Such systems are expected to be mandatory on new cars sold in the EU from May 2022 which should apply regulation 2021/1958 from 23 june 2021. Traffic signs can be analyzed using forward-facing cameras in many modern cars, vehicles and trucks.