Natural experimental study of no car zones implemented outside schools: potential and lessons learnt

Abstract

IntroductionWalking and cycling can be beneficial to health. Restrictions for motor vehicles outside schools could be one way to encourage activity but few evaluations exist. We aimed to explore the potential of such a scheme on children's active commuting, intervention mechanisms, and the utility of routinely collected data for evaluation. MethodsRestricted access for motor vehicles on road sections directly outside two Cambridge schools (one primary school [5–11 years] and one secondary school [11–16 years]) were implemented in April 2021. Teachers conducted hands-up travel surveys in March and May, 2021. All schools had facilities for storing bikes. Online surveys were distributed to parents, staff, local residents, and business owners between May and July, 2021, to assess travel behaviours and perceptions. We conducted observations at schools and interviews with a survey subsample to gain insights into intervention mechanisms, analysed using a thematic approach. Data for air quality and traffic volumes were available from February to September, 2021. Findings457 respondents completed the online survey, 13 interviews were conducted, and 40 classes completed both hands-up surveys. 18 (15%) of 117 primary school children and 30 (68%) of 44 secondary school children travelled to school without adult supervision according to parental reports. Hands-up survey data indicated no change in active commuting at the secondary school and a 2% increase at the primary school. The schemes improved perceptions of safety for pedestrians and cyclists at the primary school; however, residents still had concerns as motorists' compliance and safety were highlighted as key issues in both schools. Routinely collected, continuous air quality data were found to be particularly useful, but traffic volume data were less useful because of the timing of data collection and cost of sensors. InterpretationIt is possible that such schemes implemented with enforcement are necessary but not sufficient to encourage changes in commuting. Before a larger study could be done, the scheme design needs refinement to improve potential effectiveness. FundingUK Medical Research Council.