Analysis of Overtaking Maneuvers to Cycling Groups on Two-Lane Rural Roads using Objective and Subjective Risk

Abstract

In Spain, the presence of cyclists’ groups riding on two-lane rural roads in a single file or in parallel line is growing. The number of overtaking maneuvers to them is also increasing. This is one of the most dangerous interactions between motor vehicles and bicycles. However, the risk of these maneuvers has not been analyzed in depth. This research analyzes the objective and subjective risk of overtaking maneuvers to cyclists’ groups. During this maneuver, the motorized vehicle overtakes the bicycles with a certain speed and lateral distance. These are the surrogate measures used to analyze the objective risk, whereas the subjective risk was analyzed based on the subjective risk perception that 10 cyclists riding instrumented bicycles (in different group configurations) indicated when every motor vehicle overtook them. Results show that the cyclists most exposed to the overtaking maneuver are those at the front and at the rear of the group. In relation to the configuration, the risk is higher in parallel lines, as the lateral clearance is lower compared with a single line. It is even higher when the overtaking maneuver is flying, which is usually performed at higher speeds and lower lateral clearance. The subjective risk perception increases with higher speed and lower lateral clearance, and is higher at the rear positions. Overtaking in which lateral distance is less than 1.5 m is perceived as the riskiest. These results provide scientific recommendations to enhance safety for cyclists’ groups, and to integrate cycling with vehicular traffic on two-lane rural roads.

Driver Behavior When Overtaking Cyclists Riding in Different Group Configurations on Two-Lane Rural Roads

“…The two-abreast configuration of cyclists’ groups presented a lower lateral clearance on most road segments analyzed. These results agree with [ 23 , 24 ], where a group of 3 and 10 cyclists were analyzed, respectively.…”

“…On the other hand, it will be interesting to relate the level of risk perceived by cyclists in each overtaking maneuver. These results have already been analyzed for the group of 10 cyclists [ 24 ]. However, other sizes and configurations of the group of cyclists should be incorporated.…”

“…They found that when cyclists rode two abreast, drivers overtaking leave lower lateral clearance, and that the overtaking vehicle speed is higher when individual cyclist is passed [ 23 ]. López et al [ 24 ] increased the number of cyclists in the group to 10 cyclists, riding in different configurations. They analyzed the objective and the subjective risk of overtaking maneuvers to cyclists’ groups, using as surrogate measures the speed and the lateral distance.…”

Analysis of the Influence of Sport Cyclists on Narrow Two-Lane Rural Roads Using Instrumented Bicycles and Microsimulation

“…The effect can be noticeable on narrow rural roads, where cyclists usually ride two-abreast, causing a higher follow-up of the group of cyclists before overtaking them. López et al [20] stated that when cyclists ride two-abreast the width of the group is higher; therefore, most overtaking manoeuvres are carried out with opposing lane occupation, and more accelerative overtaking maneuvers are registered.…”

“…López el al. [20] studied the perceived risk of a group of ten cyclists when riding in different grouping configurations, and they stated that when cyclists ride two-abreast the overtaking speeds and the lateral clearances were lower, and more accelerative overtaking maneuvers were performed. Accelerative maneuvers are perceived safer by cyclists; lower overtaking speeds and higher lateral clearances were perceived safer as well.…”