Impact of holding umbrella on uni- and bi-directional pedestrian flow: experiments and modeling

In this paper, the impact of holding an umbrella on the uni- and bi-directional flow has been investigated via experiment and modeling. In experiments, pedestrians walk clockwise/anti-clockwise in a ring-shaped corridor under the normal situation and holding umbrella situation. In the unidirectional flow, the flow rate under the holding umbrella situation decreases from 0.1 to 0.25 ped/s/m when compared to the normal situation. In the holding umbrella situation, the bidirectional flow rate even reduces to 0.2 ped/s/m in contrast to the unidirectional flow. In the bidirectional flow, pedestrians segregate into two opposite moving streams very quickly under the normal situation and have right-walking preference. Under the holding umbrella situation, spontaneous lane formation also occurs. However, pedestrians can easily separate into three or four lanes. Moreover, the merge of lanes is observed, and clockwise/anti-clockwise pedestrians are not always in the inner/outer lane. The simulation results by an improved social force model considering the umbrella size are in agreement with the experimental ones.

本文通过实验与建模手段，探究了手持雨伞对单向及双向行人流的影响。实验中，行人在环形走廊内分别于正常无伞状态与持伞状态下，沿顺时针/逆时针方向行走。在单向行人流场景下，持伞状态的行人流率相较于正常无伞状态下降至0.1~0.25 ped/s/m；而在持伞状态下，双向行人流率相较于单向行人流状态，甚至进一步降至0.2 ped/s/m。双向行人流在正常状态下，行人会快速分离为两股相向运动的流束，且具有靠右通行的行为偏好。持伞状态下同样会自发形成通行车道，但行人却更容易分离为3至4条车道。此外还可观测到车道合并现象，且顺时针/逆时针行走的行人并非始终分布在内侧/外侧车道。本文采用考虑雨伞尺寸的改进型社会力模型（Social Force Model）开展仿真，所得结果与实验结果吻合良好。