Mobile mapping for the automated analysis of road signage and delineation

A portable mobile stereo vision system designed for the assessment of road signage and delineation (lines and road studs or ´cat eyes´) in low light conditions is presented. This novel system allows both geometric and photometric measurements to be made on objects in a scene. Using the system, it has been shown that retro-reflectors, and in particular road signs, can be identified by nature of their reflective properties. In addition, a novel imaging application has been investigated that facilitates the detection of defective road studs. Any objects examined can also be positioned on a national grid through the fusion of stereo vision with global positioning system technology. Automated feature extraction and analysis routines make the system fully autonomous.