Mapping Informal Mobility: A Comparative Study of GPS Tracking of Motorcycle Taxis to Better Understand Users’ Behaviors Between University Campuses in Vietnam

Rapid urbanization in Southeast Asia has intensified pressures on urban transportation systems, with motorcycle taxis emerging as crucial informal transport services in cities especially. This study examines the spatial behavior of informal motorcycle taxi services in Ho Chi Minh City, Vietnam, focusing on the UEH University campus. Using 201 recorded GPS trips, space syntax analysis, and user surveys, the research explores how spatial configuration influences movement across trip types - short (≤2 km), medium (2–5 km), and long (≥5 km). Metrics such as Global Choice, Choice_R2, Choice_R3, Integration_HH, and Connectivity were computed. Findings show that short trips concentrate on highly connected local grids (e.g., campuses, hospitals), medium trips align with neighborhood connectors (e.g., schools, offices), and long trips follow arterial routes toward commercial centers or transport hubs. Nighttime and off-peak trips displayed higher average speeds than daytime trips, especially for longer distances. User behavior insights highlight convenience, flexibility, and traffic avoidance as key motivators. The study reveals a gap between planned urban structure and lived mobility, positioning informal transport as essential for first-last mile access. By combining spatial metrics and behavioral data, the research offers a framework for incorporating informal modes into urban mobility planning to improve accessibility and reduce congestion.