Complex interventions to reduce car use and change travel behaviour: An umbrella review.

Introduction: Car travel is associated with increased risk of morbidity and mortality, physical inactivity, traffic collisions and casualties, and air and noise pollution. Effective interventions are required to reduce car use and change travel behaviour to sustainable modes. We conducted an umbrella review: 1) determine effective interventions and intervention components to reduce car use and change travel behaviour; and 2) determine where effective components are situated by level of delivery (micro-, meso-or macro-level).Methods: Five databases were searched (2000-2022) for reviews implementing a systematic re-view process. Data synthesis involved the identification of effective intervention approaches and components and the structuring of components by delivery level. Reviews' methodological quality was graded. Reviews were assessed for effectiveness (negative, null, positive or inconclusive) and consistency of results (consistent or suggestive).Results: Searches identified 20,451 records, with 18 included. Eight reviews (moderate quality) were positive consistent (n = 6) or positive suggestive (n = 2) and focused on active school travel (n = 5), walking for transport (n = 1), organisational travel plans (n = 1) and teen mobility (n = 1). One active travel review (workplaces, low quality) was rated positive consistent, with the remaining positive consistent/suggestive reviews having critically low quality: car sharing (n = 1); passive to active travel (n = 1); soft interventions (n = 1); car use reduction (n = 2); and walking school buses (n = 1). Other moderate quality reviews were inconclusive (promotion of walking and cycling (n = 1) and bicycle active school travel (n = 1)) and null consistent (behavioural interventions, n = 1). The majority of effective components were micro-level, with no investigations into intervention cost-effectiveness or inequalities.Conclusions: This review highlighted evidence to support active school travel, teen mobility, organisational travel plans and walking for transport as effective interventions. When combined,

Automated summary

Car travel is associated with various negative impacts such as increased risk of morbidity and mortality, physical inactivity, traffic collisions and casualties, and air and noise pollution. This study aimed to identify effective interventions to reduce car use and change travel behavior, and determine the level at which these interventions are delivered.