The decline in active school transportation (AST): A systematic review of the factors related to AST and changes in school transport over time in North America.

Active travel to school has declined during the last 50years in North America. During the last decade, the children's active school transportation (AST) literature has grown. This systematic review provides an updated examination of AST correlates, and discusses why school travel mode (STM) share may have changed over time. AST trends are described and a systematic literature review of AST correlates in North America for the period 1990-2016 was conducted. Strength of association between correlates and AST, and relationship direction are assessed and reported. Graphical presentation of correlates included in ≥5 studies were included. Sixty-three studies were identified and reviewed. Distance to school was most strongly associated with AST. Individual, parental and societal correlates had moderate positive associations with AST including: child age, lower parental education, income and other income related factors, race and positive perceptions of AST. Longitudinal studies were few in number, as were studies about exceptional populations, policy, and interventions. AST intervention should focus on key AST correlates. Social and environmental diversity calls for local solutions to school travel challenges. Changes in AST correlates over time should be considered for evaluating existing policy approaches, and to support development of new policy, regulation, design, and program interventions.