Introduction: Transport-related physical activity (TPA) can provide convenient, regular bouts of physical activity, and is consequently a key health priority in many countries. However, the majority of previous research in this area has been restricted to subjective self-report methodologies. The recent development of portable and non-invasive Global Positioning System (GPS) units provides researchers with the opportunity to objectively assess the location of physical activity. This feasibility study combined GPS, geographical information systems (GIS), and accelerometers to map the daily TPA patterns of working adults. Methods: A convenience sample of 40 Auckland University of Technology employees wore omnidirectional accelerometers (Actical; Mini Mitter, Bend, OR) and portable GPS units (Trackstick II; Telespial Systems Inc., Marina Del Rey, CA) for seven consecutive days. Accelerometer and GPS data were integrated into a GIS database to investigate the spatial context in which TPA was performed. Results: Several pragmatic difficulties related to GPS battery limitations, loss of signal, and participant non-compliance were identified during data collection. This was reflected in the relatively poor GPS data quality: the number of useable days ranged from 0 to 5 across the sample (average of 2.1 useable days). Nonetheless, comprehensive information describing the relationship between TPA and the built environment was obtained for the days that were retained for analysis. Conclusion: While this feasibility study highlights the complications that can arise when using GPS to monitor free-living behaviour, we suggest that the potential benefits of an objective assessment of TPA warrant further refinement of GPS as a research instrument.