Detection of unmapped road links by utilizing off-link probe data

In this paper, a practical method is proposed to use probe data for detecting locations of possible unmapped links automatically. Firstly probe data are matched to an existing road network based on their distances to links. If the distance is greater than a threshold value, the data is identified as an off-link data. Then a Probability Scoring System (PSS) is developed for categorizing the off-link probe data into three groups "Facility", "Noise" and "Link". A ranking method is finally developed for automatic outputting the locations with the highest possibility of unmapped links. Case studies in some areas are provided as evaluations of the proposed methods.