Dynamic Activity-Travel Diary Data Collection Using a Global Positioning System–Enabled Personal Digital Assistant

Activity-based transportation models have set the standard for modeling travel demand for the last decade. It seems common practice nowadays to collect the data to estimate these activity-based transportation models by means of activity-travel diaries. This paper presents a general functional framework of an advanced data collection application for activity-travel diaries to be deployed on a Global Positioning System–enabled personal digital assistant. The different modules, the building blocks of the application, are reviewed as well.