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.