Models are used to simulate pedestrian behaviour for safety at mass events, yet these models often neglect the psychological factors influencing collective behaviour. Over two studies, we explored the role of group identification on pedestrian movement, both in unidirectional and bidirectional flow. Results suggest that group members will collectively self-organise their speed and distance walked in order to maintain close proximity and avoid outgroup members. Based on these studies, I make suggestions for including group behaviour in pedestrian models and broader implications for safety planning. https://vimeo.com/531297941