The use of big data is expected to contribute to effective infrastructure planning, development, and operation in developing countries due to its accessibility and affordability to the big data. However, even in case of planning and design of urban and transport infrastructure supported by Japanese government, various physical traffic surveys including large-scale person-trip surveys and traffic count and interview surveys are still in a common exercise, and big data is not effectively utilized in the field of planning and design works in most developing countries. This study examines GPS probe data in Lao PDR and compares it with a person-trip survey conducted in the same country to understand the characteristics of GPS data and issues in trip estimation and definition, and to verify the applicability of GPS data to urban and transportation infrastructure planning and design in developing countries.