To activate the recognition of road signs, one of the side arrows on the left steering joystick must be selected from the "Auxiliary Systems" menu. It has to be down to the point "Road Signs Recognition System", enter it and press the "OK" button. The system uses video cameras to identify the signs and is also guided by the navigation system and the SDA.
The road sign recognition system installed in the Mercedes E-Class (W212) is called Speed Limit Assist. It is capable of identifying signs prohibiting speed overtaking, signs lifting these restrictions, as well as a circle of circular motion and "brick".
The identification of the sign, according to the information given on the manufacturer's official website, occurs very quickly, in the hundredths of a second. If the speed limit is valid under certain weather conditions, the display is explained. Also, even in the absence of signs, the system may indicate the speed at which another type of road, such as motorways, through a builtup area, etc. can be accepted.
Bad weather, dark time of day, windshield pollution, a large number of installed signs and other factors may prevent its work.
