This report is about a research conducted at the institute for road safety research as a Bachelor final assignment. The aim of the research is to find if there is a relation between complexities at intersection and the amount of bicycle crashes. The overall goal is to find specific complexities or characteristics of intersections that influence the amount of bicycle crashes to improve the safety in the future. The relation between the bicycle crashes and the complexities are conducted with two methods. The first one, conflict points method, focusses on the intersection plane. It counts the number of times two driving lines intersect each other (a conflict point). There will be looked for a relation between the total number of conflict points and bicycle crashes, as well as some special types of conflict points. The second method is the PIARC method, this method focusses on the road sections leading to the intersections just in front of the intersection plane. It determines which characteristics are attendant and gives a total score for the complexities. Between the PIARC score and the amount of bicycle crashes is looked for a relation. Next to the total PIARC score every single characteristic is checked whether they have a relation with the amount of bicycle crashes. The relations are determined with the help of negative binomial distribution models. In each model the traffic flow of the bicycles and cars are taken into account as offset variables, since these also influence the amount of bicycle crashes. Also, other characteristics will be investigated if they have an influence on the amount of bicycle crashes. The results of the research show that there is no relation between the conflict points and the amount of bicycle crashes. For each of the tested types of conflict points there was no relation found. The PIARC method shows different results. The more complex the intersection is the less bicycle crashes occur. This is substantiated by most of the individual characteristics, they show the same relation. Other characteristics of intersections that were tested show that there is a higher amount of bicycle crashes at 4-way intersections than 3-way intersections. Based on the results it is advised to add complexities to intersections, especially bicycle facilities, to decrease the number of bicycle crashes at intersection. For future research, it is advised to take a bigger sample of the bicycle crashes by expanding the timeframe when these data were collected or use another source, if this is available, to increase the accuracy. The more accurate data can be used to determine if there is a relation between the insignificant factors and the amount of bicycle crashes or to confirm what was found in this research. Furthermore, it is important to have a good look at the conflict points method, since the results showed no relation where a relation was expected. Also, the mutual relation of complexities and their influence on the amount of bicycle crashes could be investigated in future research. The conclusion of the research is that there is no relation between the conflict points and the amount of bicycle crashes, but there is a relation between the PIARC method and the amount of bicycle crashes. The more complex an intersection is the less bicycle crashes occur. Probably caused by more complex looking intersections where people pay attention and all the characteristics guide road users over the intersection. (Author/publisher)
Abstract