Collecting data on who is traveling where, when, and why is possible with the Global Positioning System Automated Travel Diary (GPS-ATD), which has an intuitive user interface that collects trip information with limited user input and hassle, and wireless that ties personal and vehicular GPS-ATD units together, resulting in a unit that could be useful for the 2010 California Statewide Household Travel Survey. Better planning after attaining improved understanding of traveler behavior can increase the capacity of transportation systems without new construction. Conventional cross-sectional survey methods provide traffic loading at a specific location over time, while longitudinal surveys directly measure traveler behavioral change at the level of the individual traveler and provide information leading to improved understanding of the factors that affect and direct personal travel behavior. Household longitudinal travel surveys gather three categories of data: household information, household member personal information, and travel activity for specific days. However, collecting complete data via travel surveys is difficult. The advanced and highly integrated design of the GPS-ATD enables the GPS-ATD to provide many improvements beyond previous travel survey methods. The present GPS-ATD is a first-generation proof-of-concept prototype, and many enhancements influencing the cost, size, and technical performance of the overall system are necessary before mass production and final deployment. The personal units GPS performance is not ideal because the GPS signal amplification sub-block, principally the LNA, is susceptible to interference from other on-board components. Post-processing and automation will be critical for the full-scale use of the GPS-ATD in a real-world travel behavior survey such as the 2010 survey for California. Such a survey would yield large and complex sets of spatiotemporal data, and evaluation of this data will demand the development of appropriate techniques and tools to support and facilitate extraction and reporting of useful survey data.