Social groups exhibit some degree of social cohesion that is more than a simple collection or aggregation of individuals. The study on behaviours of social groups is essential to gain a deeper understanding on pedestrian dynamics. In this paper, the crowd movement among individuals and social groups are studied by performing a series of multidirectional pedestrian flow experiments under laboratory condition. Interestingly, we found that the speed of individual is not always higher than that of

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... ocial groups. Pedestrians try to use different strategies to arrive their destination. With different strategies, their speed and movement time show different properties. These findings may provide basis for facility design and evacuation plan.