Social groups barely change the speed-density relationship in unidirectional pedestrian flow, but affect operational behaviours

Pedestrian crowds are not homogeneous. One common distinguishing characteristic is the membership in social groups based on friendship or families, for example. It important to understand how these affect pedestrian dynamics inform their consideration safety planning. Despite previous work groups, there a paucity of controlled experiments effect under normal conditions which crucial delineate relative risks pedestrians non-emergency situations. To address this, we present results from influence dyadic unidirectional flow. We consider comprised 100%, 67%, 0% groups. Our experimental setting crowd densities between 1.25 and 4.0 per m2. find that while relationship speed density affected by presence size this smaller than overall variability observations. In contrast, clear differences movement individuals Social move at slower speeds overtake others less frequently. Regardless density, further away next-closest are, suggesting larger empty space around These findings suggest when need be considered management modelling conditions. At macroscopic level, described speed-density relationships, explicitly but considering microscopic including overtaking personal space, they should explicitly.