The Effect of Wheelchair Users on the Egress Time of Pedestrian Crowds: A Systematic Literature Review and Meta-analysis

Egress time, or how long it takes a pedestrian crowd to pass through a bottleneck during egress, is a crucial metric for safety and capacity considerations. It has been suggested that heterogeneity in the composition of pedestrian crowds - such as variability in mobility, age, or the presence of social groups - could affect egress times. However, only a few empirical studies have addressed this issue. To solidify insights from the existing empirical evidence, we present a systematic literature review and meta-analysis to quantify if the presence of wheelchair users in pedestrian crowds increases egress times. We identified nine studies, all based on controlled experiments, that used a comparable layout in which groups of participants had to move through a bottleneck and compared conditions with and without wheelchair users present. The meta-analysis confirmed the findings from the individual studies. The difference in egress time between conditions with wheelchair users present and those without was close to three standard deviations, indicating a strong effect. We found no evidence for publication bias, such as the under-reporting of non-significant findings. Our work presents a quantitative basis for adjusting expected egress times depending on occupant characteristics. It suggests that the behavioural consequences of crowd heterogeneity are safety relevant and require further investigation.