Beyond physical activity: a systematic review of the co-benefits of active travel interventions

Background: Active travel (AT) interventions may offer benefits beyond increased physical activity. However, such potential ‘co-benefits’ have not been systematically synthesized, representing a missed opportunity to engage non-health sectors to promote active and sustainable lifestyles.

Purpose: To synthesize evidence on the ‘co-benefits’ of AT interventions.

Methods: This pre-registered systematic review adheres to PRISMA and Synthesis without Meta-analyses (SWiM) guidelines. Experimental/quasi-/natural experiment designs targeting AT behaviour, with a control group/condition and assessing physical activity outcome/s and co-benefit outcome/s were included. Systematic searches were conducted from January 2000 until September 2022 in Web of Science, PsycInfo, PubMed, Cochrane, and the Transport Research International Documentation. Risk of bias was assessed independently in duplicate using an established checklist. Results were synthesized using effect direction plots. Certainty of evidence was summarised using Grading of Recommendations, Assessment, Development, and Evaluations (GRADE).

Results: Of the 37,736 unique records assessed, 80 were included. Of those, 69 were quasi-/natural experiments, 11 were RCTs. Intervention context included the built environment (n=46), schools (n=25), and workplaces (n=12). Across studies, there was consistent evidence that AT interventions offered a broad range of co-benefits. Particularly, 71% (n=35 studies) showed co-benefits of improved safety, 63% showed improved health (n=30), 85% suggested economic benefits (n=20), 84% highlighted improved transport quality (n=19), 92% indicated environmental benefits (n=13), and 80% documented social benefits (n=5). GRADE assessment suggested high-certainty evidence for RCTs and very-low-to-low-certainty evidence for quasi-/natural experiments.

Conclusions: Despite low-certainty evidence from many studies, mostly limited by quasi-/natural experimental design for environmental interventions, AT interventions offer unique opportunities to engage stakeholders across sectors to ‘multi-solve’ societal problems, such as physical inactivity, traffic harms, carbon emissions, and air pollution.

Practical implications: This evidence synthesis can be used to inform the design, implementation and evaluation of AT interventions.