Using automated video analysis of traffic flows and conflicts, SWOV has studied the effects of the redesign of two intersections in The Hague, Van Alkemadelaan-Wassenaarseweg and Jonckbloetplein. For this, video images taken during before and after the redesign were linked to video analysis software. Where video images previously had to be assessed visually, this is now done automatically.
Project leader Gert Jan Wijlhuizen of SWOV: 'This method, for which several software packages are available, is undergoing rapid development. They are expected to be increasingly suitable for use in road safety research. As in this study, this may involve evaluating interventions between cyclists and motor vehicles at intersections. But it is also possible to use this method to analyze traffic processes and thus determine which locations are relatively dangerous and which qualify for measures.'
The Hague Intersections Van Alkemadelaan-Wassenaarseweg and Jonckbloetplein
At the two intersections in The Hague, the study showed that bicycle crossing has improved. The changes have resulted in a decrease in the number of conflicts between bicycles and motor vehicles at the analyzed locations, an indication that it has become safer for cyclists there.
At both intersections, the bicycle crossings have been 'bent out', i.e. placed further from the intersection plane. This improves the view of a turning vehicle on a cyclist going straight ahead at the same time. Another adjustment is that cyclists are given a separate green light in certain situations, ie without encountering crossing motorized traffic that has green light at the same time.