Methods for detecting activity-travel behavior information from passive GPS data: state-of-the-art

Due to its minimum burden for respondents, passive GPS has become a promising method for collecting individuals' activity-travel behavior data. However, passive GPS only provides information on time, position speed of movement, etc. Individuals' activity-travel behavior information concerning what (types of activities and trip purposes), where (place where activities are collected as well as trip origins and destinations), when (starting time, duration as well as trip arrival and departure times) and with whom activities are conducted and what transportation modes are used must be deduced from the raw data of passive GPS. This has been the major obstacle for applying passive GPS for collecting activity-travel behavior data. In the past years, much research attention has been directed toward develoing methods to derive activity-travel behavior information from passive GPS. The purpose of this paper is to provide an overview of the state-of-the-art developments in this research field. The paper first traces the developments of activity-travel data collection methods; emphasis will be placed on summarizing the recent developments of post processing methods from GPS raw data. Pros, cons and problems of the existing methods and algorithms for detecting individuals' activity-travel behavior information from passive GPS data will be analyzed and discussed. Prospects and potential areas for future studies in this field as well as future directions for using modern ICTs to collect activity-travel behavior data in general will be suggested.