Infrastructure Based Approach to Increase Cycling Safety in case of Turning Motorists Interacting with Crossing Cyclists at an Urban Intersection

In urban traffic, cyclists are often exposed to high risks especially when being in interaction with motorized traffic participants. In particular there have always been severe accidents in case of right turning lorries and cyclists going straight, which may result serious injuries and fatalities of the cyclists. In this paper an infrastructure based approach is introduced, which is (i) capable of detecting and assessing crash risks between motorists interacting with cyclists and (ii) emitting dedicated risk warning messages to vehicles, bicycles and visual road instrumentations. For this purpose critical and non-critical encounters have been examined to identify patterns and derive situational factors contributing to traffic conflicts between right turning motorists and straight ahead driving cyclists. These analyses are the basis for the developed situation and risk assessment system detecting and predicting safety relevant traffic situations. The design of this system will also be presented. The predictive elements are crucial to enable the system to warn before a safety-relevant event actually occurs. The approach was tested at AIM Research Intersection in Brunswick, Germany, which is an urban intersection equipped with detection sensors. The results shown in this paper were obtained in the EU funded project XCYCLE (Advanced measures to reduce cyclists' fatalities and increase comfort in the interaction with motorized vehicles, Grant Agreement number: 635975)