• This is a study with a large multi-ethnic sample (n = 740) of children from seven primary schools in Bradford, UK.

• Children's perception of the built environment influences their happiness and satisfaction with the school route.

• Safety from traffic, good sidewalks, and having things to see and do around the school boost wellbeing.

• Active school commuters enjoy their journey more but are not necessarily happier overall.

• Cities should enhance streets near schools (e.g. traffic safety, sidewalks, things to see and do) to promote child wellbeing.

Background. The urban built environment can impact children's wellbeing through exposure to health hazards or conditions that hinder or promote street activities (e.g. active travel, leisure). Children's travel to school is an important way children interact with their environment. However, little is known about the relationship between children's perceptions of the built environment on the route to school, travel mode and the impact this has on their subjective wellbeing.

Methods. Using a bespoke questionnaire, we gathered children's perceptions of the built environment on their school journey (including home street, trip and road outside the school characteristics), frequent active travel to school (3+ days/week) and three wellbeing outcomes: liking the journey, feeling happy and relaxed during the journey, and feeling happy. Multivariate logistic regression was used to explore the association of wellbeing with perceptions of the built environment.

Results. 740 children, aged 8–11 years, in seven schools in Bradford, UK. Three built environment perceptions were consistently associated with all measures of wellbeing, feeling: safe from traffic on their trip, that sidewalks were in good condition on their trip, and that there were things to see and do near school. Frequent active travel to school and good air quality were associated with children liking their trip to school but not with feeling happy and relaxed on the journey or generally happy.

Conclusion. Our results suggest that children's perceptions of certain built environment characteristics are important predictors of wellbeing on the school journey. Policy and decision-makers are encouraged to improve the quality of these built environment features (e.g. traffic safety, sidewalks, crossings, and having pleasant things to see and do) to foster children's wellbeing.