A Comparison of GPS and Travel Diaries to Characterize Walking Behavior

While travel diaries are widely used to investigate walking behavior, the emergence of portable GPS units provides an innovative approach to characterizing walking behavior. This study compares the number and duration of daily walking trips reported in travel diaries with data extracted from a portable GPS unit and identified as the same walking trips. The study had two phases: (1) We used 35 person-days of travel data to determine the best algorithm for identifying walking trips from GPS data. The best algorithm had high Pearson (0.89) and Spearman correlation (0.85).