Shortest path distance vs. least directional change: Empirical testing of space syntax and geographic theories concerning pedestrian route choice behaviour

Existing knowledge on the impact of built environment (BE) on route choice behaviour is doubtful due to an unresolved tension between two schools of thought. One represented BE geographically and found that most people tend to choose the shortest route. The other represented BE topologically and showed that least directional change is a key determinant of route choice. How do pedestrians make a trade-off between these two factors in route choice? This question is answered using walking route data of 178 pedestrians in Brisbane, Australia. Their reported routes were examined against the corresponding shortest path and least directional change routes using the percent overlap method. The effects of 25 additional BE factors were also estimated in a conditional logit model. The results reveal that: (a) Together distance and direction are likely to explain 53% of route choice decisions; (b) Individually, distance and direction are likely to explain 34% and 46% of route choice decisions respectively; (c) 28% of the chosen routes satisfied both distance and direction criteria. These findings confirm the claims of both schools, but also point that the least directional change route is a preferred option, and that pedestrians tend to minimise both criteria if they can.