USING GLOBAL POSITIONING SYSTEMS AND PERSONAL DIGITAL ASSISTANTS FOR PERSONAL TRAVEL SURVEYS IN THE UNITED STATES

This project combined Global Positioning Satellite (GPS) and Geographic Information Systems (GIS) technology with small hand-held computers (Personal Digital Assistants - PDAs). In addition, respondents were mailed a training video to assist with installation and use of the equipment. A small, user-friendly, mail-able unit was designed to capture vehicle-based, daily travel information. Nearly 90% of person trips in the U.S. are made in a private vehicle. The unit was developed to capture variables that would be entered by the vehicle driver using a touch-sensitive menu, with items such as trip purpose and vehicle occupancy, and to capture automatically recorded variables such as date, start time, end time, and latitude and longitude at frequent intervals. Finally, after mail-back return of the units, the data are processed to include variables such as travel speed by road classification, trip distance, and trip time. The unit allows for collection of travel data over several days to avoid potential short-term, survey-induced travel behavior changes. This method of data collection has two potential benefits: improving the quality of travel behavior data, and reducing respondent burden, e.g., time on the telephone for reporting travel information. Using GPS technology, while increasing privacy concerns, may improve overall survey data quality in travel behavior studies. The field test was conducted in Lexington, Kentucky, in Fall 1996, with 100 households. The sample of drivers was stratified by age, gender, and presence of children under age 16 in the household. Respondents were asked to use the machine for six days, with the expectation that data from Day 1 and Day 6 many not be useable. Respondents were also asked to recall all their travel for one 24-hour period (Day 5). This process resulted in a complete 24-hour report of trips made by the selected driver by all modes and a 4-day report of trips made in the selected vehicle by all drivers and passengers. Geographic coding of destinations should be much improved using the GPS technology. Also, route choice, functional class usage, and travel speed information is available. This paper focuses on respondents' perceptions on the installation and use of the equipment. Some comparisons between self-reported and machine-recorded travel are discussed, but are limited.