Conversion of Volunteer-collected GPS Diary Data to Travel Time Performance Measures

(PI: Chandra Bhat, CoPIs: Prof. Barbara Parmenter, Stacey Bricka, and Siva Srinivasan)

Household travel survey data constitute a fundamental input to travel demand model development for use in transportation planning and policy analysis. Conventional travel survey methodologies require the collection of detailed address and travel information, which impose a significant burden on potential respondents, thereby adversely impacting the quality and quantity of data obtained. The Global Positioning System (GPS) technology, because of its passive and accurate data collection capabilities, has the potential to reduce the dependence on travel surveys. The data recorded by GPS devices, however, does not directly yield travel information; the navigational streams have to be processed and the travel patterns derived from it. This research proposes the development of a prototype software for automating the conversion of raw GPS data (obtained from in-vehicle GPS devices) into a traditional activity-travel diary data set. The software will identify trips, and characterize them by several attributes including trip-end locations, trip-purpose, time-of-day, distance, and speed. The results will be presented to the analyst in a tabular form and/or on a GIS map, as desired. Further, the software will also be capable of aggregating the derived trip diary data to produce trip tables (by purpose and time of day) and to compute highway performance measures such as inter-zonal travel times and speeds (by time of day).