Experimental study on the zebra crossing traffic flow characteristics of mixed bicycles and pedestrians

Slow transportation mode, consisting of walking and cycling, plays an important role in the urban traffic system. To analyze the influence of additional bicycles on the traffic efficiency of the bicycle-pedestrian mixed group on the zebra crossing, we conducted controlled experiments to study their traffic flow characteristics based on the micro-characteristics of individuals and the macro-effect of bicycle proportion in the mixed group in which bicycles and pedestrians often share the common road facility in some countries. This work constructs a 10 m-long, 3 m-wide passageway to mimic the zebra crossing area. We first extract the head trajectories of cyclists and pedestrians to quantitatively analyze the speed, density, and spatial relationship among them through the videos that record the complete process of the bicycle-pedestrian mixed experiments. Our quantitative results show that increasing the bicycle proportion leads to longer travel and passing time because of the large personal space requirements for cyclists. By analyzing the spatial relationship and recording the forward and lateral distance between the two nearest individuals, an improved theoretical formula is proposed to describe the passing time for unidirectional bicycle-pedestrian mixed flow on zebra crossing and provide traffic efficiency. The analysis indicates that a smaller personal space for cyclists can shorten the passing time effectively. These findings are the first step toward developing bicycle-pedestrian mixed flow on the zebra crossing, which contributes to providing practical implications for planning and designing bicycle and pedestrian shared infrastructures.