Advanced real-time intersection data collection system for safety evaluation

Many signalized intersections are associated with vehicle crashes due to dilemma zone issues. Dilemma zones are defined in either time or space, as zones where some drivers may decide to proceed, and some may decide to stop at the onset of yellow. Dilemma zone can therefore lead to rear-end crashes, when a driver decides to stop while their follower decides to proceed, and/or right-angle crashes, when drivers end up violating the red-light, to crash with side street traffic. Many algorithms and real-time dilemma-zone protection systems were developed. In order to evaluate these algorithms, Virginia Tech Transportation Institute (VTTI) developed an advanced real-time intersection safety data collection system. This system monitors the intersection phase and detector actuations as well video captures of red-light-runners. This paper presents the data collection system and shows preliminary data collection results in two sites in Illinois. The system was used to collect traffic volume profile, number of vehicles captured in dilemma zone, and videos of red-light-runners.