BMW has the best traffic-sign recognition systems, according to a test by Germany’s largest auto club, the ADAC.
The testers compared systems on a BMW 740d, a Mercedes S 500 CGI, an Audi A8, an Opel Insignia and a VW Phaeton. BMW won the comparison, both in recognizing traffic signs and in projecting them on the car’s head-up display.
With the exception of Opel, all systems uses a combination of cameras and maps to detect speed-limit signs. Data are “seen” by the cameras and then matched with navigation-system maps. The Opel system relies completely on the vehicle’s cameras.
Opel's technology goes beyond just speed-limit signs and also recognizes no-passing signs. VW has promised to have this feature as well shortly.
The ADAC tested both recognition and display. All systems had problems with variable speed-limit signs that are increasingly used on major highways . The LED technology used in these signs is difficult to recognize for onboard cameras.