For the purposes of this research, TNO studied the behaviour of cyclists on several busy cycling paths. With the help of the so-called DOCTOR-method (Dutch Objective Conflict Technique for Operation and Research), the nature and seriousness of conflicts between cyclists was identified and recorded.
According to the images, there were considerably more conflicts on the narrow 1.75-metre cycling path than the other two wider paths that were investigated. The intensity of cycling, narrow width, and the limited fallback or avoidance possibility contributed to a relatively high number of conflicts during passing maneuvers. Crossing traffic also contributed to a higher number of conflicts. In addition to the narrow width, the bustle and presence of pedestrians and objects on the cycling path played a role. Based on these findings, TNO concludes that a 2.25-metre wide cycling path in the city results in few serious conflicts. But based on observations of conflicts involving mopeds, a 2.50-wide metre cycling path is recommended if mopeds use it. It is also important to create more space at points were cyclist merge onto another path. If it is not possible to widen the entire cycling path, then the construction of an access lane is also a solution according to TNO.
The most serious conflicts have been observed by TNO on recreational cycling paths during the weekend. From the camera images one can conclude that a 4-metre wide cycling path (2 metres each way) promotes safety, even in the event of a conflict between cyclist riding in opposite directions. It is notable that cyclist give the shoulder a wide berth, probably as a result of “shoulder-phobia”. Forgiving shoulders on recreational cycling paths invite the use of the full width of the cycling path, thus effectively providing more room to cycle in parallel and to pass. According to TNO, safety could be significantly increased by separating different ranges of cycling speed on the recreational paths, for instance by situating two fast lanes in the middle of the path, one for each direction.