Prompted Recall in Global Positioning System Survey: Proof-of-Concept Study

Modeling procedures in transportation planning depend on the quality of data collected from personal travel surveys, which in turn depend on the data-collection technique. All conventional data-collection techniques rely on respondents to report the time, distance, and location attributes of a trip, among other things. Respondents rarely know addresses that they visit with sufficient detail to permit accurate geocoding. Also, it has been observed that short trips are underreported. Earlier studies proved the feasibility of using the Global Positioning System (GPS) as an alternative to acquire error-free, high-quality information on trip-making behavior. However, all GPS survey methodologies tested relied on the respondent to enter information into a personal data assistant (PDA) as the trip is being made and to intervene in other ways to record all data for each trip. This adds the expense of a PDA and its power supply and puts a burden on the respondent. A method that uses GPS technology with less complexity, involving less cost and minimal user intervention while making the trip, is tested and explained. Additional trip attributes that cannot be recorded by the GPS receiver were obtained after the survey period by prompted recall, in which the respondents were aided with maps displaying their travel paths. Analysis of the data showed that this method performed very well. However, a still-larger survey is needed to estimate the benefits.