Research On Pedestrians' Properties And The Guidance Strategies Under Open Environment

Recently, with the rapid development of national economy and urbanization, cultural and leisure lives of urban residents become rich increasingly. More and more residents leave their house to participate in types of cultural and leisure activities. As a result, pedestrians become more intensive in various public places. However, walking is the most important transport mode. High concentration of pedestrians will not only bring certain pressures to kinds of infrastructure, but also take great risk to the safety of pedestrians. The external factors, i.e. structures of infrastructure, setting of traffic signals and unreasonable of traffic rules, may be a security risk to pedestrians'safety, and these are mainly attributed to a lack of in-depth understanding of walking characteristics of pedestrians, evolution features of pedestrian flow etc., so that those facilities can not be utilized efficiently. Additionally, pedestrians will not obey these traffic rules, leading to various traffic accidents of pedestrians. For these reasons, it's necessary to make clear the pedestrian flow mechanism in microscopic level. Only in this way can we use a more scientific theory to guide pedestrians'behaviors and develop more reasonable, effective and human traffic regulations, which can effectively solve the increasingly serious problems of pedestrians'traffic safety. The main research contents are as follows:1. Firstly, we extend a cellular-automata model recently proposed by Baek et al. to simulate traffic dynamics of the bi-direction pedestrians. And two improved strategies are presented for the moving rules of the pedestrians. One is that, when an ignorer can not move forward for being blocked by the pedestrian in front of him, he will consider moving towards the side with less pedestrians. Another is that, when a pedestrian can't move forward or left or right, if he is an abider, he will choose to move backward after staying for one time step, otherwise he will move backward immediately. Numerical studies are given with respect to average velocity-density diagram, spatial density distribution and position distribution of the pedestrians. We find that the two improved strategies can not only increase the average velocity of pedestrian flow, but also improve the utilization of the road, especially for the central region, and reduce the degree of congestion. Then, in the case of fixed road length, the effects of different road width on the whole system of pedestrian flow are analyzed. The results show that, different road widths certainly have some impacts on pedestrians'average velocity, congestion degree and road utilization.2. Takimoto et al. introduced a partition line on the center of the channel firstly in 2002 and showed that the partition line can efficiently improve overall flow of the channel system. However, they only considered single type of pedestrians. In fact, both traffic abiders and ignorers coexist on road. Therefore, based on the idea of a partition line and walking strategies of the bi-directional pedestrian model recently proposed by Back et al., we establish our models from the perspective of pedestrians walking strategies. The strategies consider both behaviors of traffic abiders and ignorers outside the partition line, and numerical simulations are carried out. The results show that, the introduction of a partition line is in favor of improving critical density of pedestrians' flow, reducing congestion near the boundaries of road, reducing traffic interruption between ignorers and abiders, improving the utilization of road. Finally, we investigate the impacts of different pedestrian proportions and channel widths on pedestrian flow characters.3. The analysis mentioned above is all based on counter flow in two-sides-open environment, i.e. channel and road. As to the case of all the four sides opened, there is no consideration and research. Therefore, we develop a four-direction pedestrian flow model based on the basic idea of the two parts mentioned above. Further studies are made on impacts of different pedestrian proportions, squares'geometry proportions and sizes on pedestrian flow characteristics. The simulation results show that, with the introduction of guide facilities in the square, pedestrians'flow is relatively stable, and no obvious congestion occurs. In addition, the existence of certain traffic abiders is helpful to improve the critical density and system utilization.