Analysing pedestrian walking speed on overhead footbridges: the role of demographic and temporal factors in an emerging urban context

This study investigates pedestrian walking speed across three overhead pedestrian footbridges in Freetown, Sierra Leone, considering demographic and temporal variation. Pedestrians were observed manually over seven consecutive days, with walking time measured across the entire footbridge. A total of 3,094 valid observations were recorded, and walking speed was estimated from crossing time and bridge length. Three-way factorial ANOVA was complemented by heteroscedasticity-robust and linear mixed-effects modelling following assessment of model assumptions. Estimated marginal means and Tukey-adjusted pairwise contrasts were used to interpret significant interactions. Age group was revealed as the dominant determinant of walking speed, with elderly pedestrians consistently walking substantially more slowly than children and youth/adults. A significant age × gender × day-group interaction indicated that demographic effects varied across temporal conditions. Female youth/adults walked faster than males on weekdays, while elderly females walked faster than elderly males on weekends. Weekday speeds were higher among female children and elderly males. Although the observed speeds were substantially below conventional normal walking speeds reported for controlled walkway conditions, unit and plausibility checks confirmed the measurements. The findings represent facility-specific operational walking speeds and highlight the need for locally derived and demographic-sensitive pedestrian speed parameters for safe and accessible overhead pedestrian infrastructure.