GPS, Location, and Household Travel

Abstract

Experiments to date with global positioning systems (GPS) devices have shown that these are viable as a means of obtaining detailed data on the trip movements and patterns of individuals in the general public. This is proving to be an increasing promising procedure to determine both more accurate data on origins, destinations, and trip lengths, and also to provide route choice data that have not recently been available. There still remain questions to be answered relating to the most effective ways to deploy such devices, privacy, and respondent burden. These issues are likely to become more significant as the technology allows a shift from in-vehicle to wearable devices. This chapter describes how the passive GPS device is clearly superior, particularly when coupled with a prompted recall survey. The proven ability to develop software that provides efficient analysis of the vast amount of GPS data that can be obtained through these devices, and produce user-friendly reports on the travel undertaken, is clearly a major asset to the further implementation of passive GPS units. Furthermore, the development of strategies to repair fully faulty data from the GPS device, such as that caused by warm-up periods and urban canyon effects, makes the technology increasingly valuable. It is possible that future GPS developments may also reduce the severity of these problems. It is unlikely that GPS will replace the standard household travel survey within the near future but it seems likely that the time requirements to deploy and retrieve the devices, analyze the data, and conduct supplemental surveys, coupled with the experience of the units themselves, are likely to make it prohibitive to conduct a sample survey of 3000 or more households using such technology.