A one-day GPS trajectory is first split into trips and each of these resulting trips is then divided into single-mode segments (hereafter referred to as segments) for this detection process. The method used for trip detection is described in one of our previous studies (Xiao, Juan, & Gao, 2015). The basic ideas underlying this study are the assumption that the trip ends take the form of either point clustering or an abrupt direction change in the case of GPS normal recording, while they present a dwell exceeding a given critical duration during signal loss. The segments are extracted from trips according to the method proposed by Gong et al. (2012). By means of a prompted recall survey, the information is corrected if necessary. There is no heavy burden on respondents as expected, since most travel information can be correctly etected. Such validated travel information is regarded as the ‘ground truth’ in the subsequent study. Each respondent is required to participate in the survey for at least five continuous days. Ultimately, 1636 person-day positioning data from 202 respondents was collected. After data screening to ensure completeness and logical behavior, 1248 person-day data streams were
retained for subsequent analysis.
A one-day GPS trajectory is first split into trips and each of these resulting trips is then divided into single-mode segments (hereafter referred to as segments) for this detection process. The method used for trip detection is described in one of our previous studies (Xiao, Juan, & Gao, 2015). The basic ideas underlying this study are the assumption that the trip ends take the form of either point clustering or an abrupt direction change in the case of GPS normal recording, while they present a dwell exceeding a given critical duration during signal loss. The segments are extracted from trips according to the method proposed by Gong et al. (2012). By means of a prompted recall survey, the information is corrected if necessary. There is no heavy burden on respondents as expected, since most travel information can be correctly etected. Such validated travel information is regarded as the ‘ground truth’ in the subsequent study. Each respondent is required to participate in the survey for at least five continuous days. Ultimately, 1636 person-day positioning data from 202 respondents was collected. After data screening to ensure completeness and logical behavior, 1248 person-day data streams wereretained for subsequent analysis.
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