What constitutes a ‘trip’? Examining child journey attributes using GPS and self-report

Active travel is associated with improved health and development outcomes in children. Accurate detection of children's travel behaviors and routes, however, is problematic. Travel diaries are often used to collect information on children's travel behaviors, yet no evidence for the accuracy of this methodology exists. This study investigated the validity of children's self-reported trips (origin, destination) compared with an objective criterion (global positioning systems units; GPS). Children (n = 10, 9–11 y) wore the GPS units for seven consecutive days between March and June 2011 and completed travel diaries daily with researcher assistance. Affinity group interviews were conducted in December 2011 with 30 children from two schools to garner perspectives on trip definition, neighborhood perceptions, and to illuminate GPS and travel diary findings. GPS journeys were manually compared with travel diary journeys for destination sequencing, start times, and travel mode. Accuracy in trip sequencing was compared by day type, and journey type using percentage differences and the chi-square (χ2) statistic. Of the 380 trips captured, 54.5% of journey sequences were fully or partially matched, 22.4% were GPS only trips and 23.2% travel diary only. Greater accuracy (full/partial match) was observed for weekdays than for weekend days and for the journey to or from school than for other journeys. Travel mode agreement existed for 99% of matched trips. Although children's travel diaries may confer contextual journey information, they may not provide completely accurate information on journey sequencing. Thematic analysis of affinity group data revealed that reasons for this are multifaceted, including differing concepts of what constitutes a ‘trip’. A combined approach of GPS and travel diary is recommended to gather a comprehensive understanding of children's journey characteristics.