Toward sustainable active school travel: A systematic umbrella review highlighting correlates and interventions

Active school travel (AST) supports children's health and contributes to urban sustainability, yet the rapidly expanding literature remains fragmented and inconsistent. This study presents the first umbrella review on AST, integrating a systematic mapping of the review landscape with a targeted synthesis of correlates and interventions. A systematic search of six databases and four review repositories was conducted in accordance with PRISMA and JBI guidelines, with the protocol prospectively registered in PROSPERO (CRD42024607002). Thirty-four reviews met the eligibility criteria and were classified into four thematic categories and nine review types. Although the Social Ecological Model was frequently employed to examine AST correlates, the evidence base remains heterogeneous, characterized by inconsistent measurement approaches, conflation of subjective and objective indicators, and imprecise construct definitions. The synthesis identified relatively robust positive associations for objective population density, perceived facility accessibility and traffic safety, whereas other environmental correlates exhibited weaker, mixed, or context-dependent relationships. Interventions to promote AST were largely framed within the Safe Routes to School paradigm, with the Walking School Bus program demonstrating particular promise. However, many intervention studies lacked solid theoretical foundations, sufficient methodological rigor, and adequate attention to systemic implementation and governance, which constrained their overall effectiveness. By identifying critical methodological and empirical gaps, this review calls for robust analytical strategies and the consolidation of existing findings to foster cumulative scientific progress. Future efforts should prioritize underexplored qualitative, longitudinal, policy-related, and technology-informed perspectives. These findings provide targeted guidance for advancing empirical research and evidence synthesis in AST and related domains. • First umbrella review synthesizing evidence on active school travel (AST) • Cross-regional prevalence comparisons warrant caution due to heterogeneous measures. • Correlate reviews remain inconsistent; intervention reviews show modest effects. • Population density, perceived facility and traffic safety are positive correlates. • Future syntheses should enhance methodological rigor and strategic coverage.