Global Positioning System (GPS) techniques have been utilized for collecting travel behavior data for a number of years. However, they often suffer from signal loss and signal blockage particularly in urban canyon environments. These problems prevent the GPS-based data collection system from providing seamless temporal and spatial data on human's activity-travel trajectories. Based on an overview of the problems and issues related to the application of GPS technologies for collecting data on individuals' activity-travel behavior, this paper proposes a data collection system that combines GPS and ground-based positioning technologies to provide continuous spatio-temporal information on a moving object in both indoor and outdoor environments. Methods for extracting activity-travel data from the continuous spatio-temporal information and visualizing the data are also suggested.