Method of assessing vehicle motion trajectory at one-lane roundabouts using visual techniques

The main purpose of roundabouts is road traffic calming by triggering a vehicle motion trajectory change before entering the roundabout and consequential traffic deceleration when crossing the roundabout area. The article provides a discussion on results of research concerning vehicle motion trajectory at one-lane roundabouts. Specific cases have been studied to analyse the effect of one-lane roundabout geometry on vehicle motion trajectory. The relevant survey was conducted by video recording a road traffic scene at a roundabout. An image thus obtained made it possible to determine what is referred to as a dipped headlight track of vehicles by application of the Harris algorithm. The vehicle motion trajectories recorded in the survey were subject to statistical analysis in order to reveal any potential regularities that could be relevant to assessment of the current roundabout geometry. The measuring method proposed is more flexible compared to other vehicle motion trajectory recording techniques, as it enables vehicular traffic to be studied under most weather and illumination conditions, including at night, in non-illuminated road sections, and even in fog.