Automatic Generation of Meaningful Virtual Direction Markers in Road Networks

Direction markers are widely used in real road networks. They show directions to important destinations such as cities, industrial areas, airports or touristic sights. In this paper, we introduce virtual direction markers that only exist digitally in, e.g., a navigation application. We present an approach to automatically compute and place such markers without additional manual editing. Our assumption: a direction marker resides on an optimal path from an arbitrary start to the respective target. However, a naïve approach would place confusing or misleading markers. Thus, we add the concept of cropping that removes unwanted markers. Finally, we introduce the notion of relevant crossings and default links that additionally improve direction markers.