Abstract
Population dependence on car use has adverse health consequences including road traffic injury, physical inactivity, air pollution and social severance. Widespread car dependence also entrenches lifestyles that require unsustainable levels of energy use. Most transport policies explicitly include goals for public health and sustainability. Transport interventions can therefore be seen as complex public health programmes, and assessing their outcomes against health and sustainability goals is vital. Using organisational travel plans (OTPs) as an example, we demonstrate how best practice epidemiological systematic reviews can be used to assess the existing evidence to inform transport policy. Such a synthesis of the evidence for OTPs has not been undertaken previously.
We undertook a rigorous systematic review in accordance with a peer reviewed protocol to assess the effects of OTPs on individual and population health. We defined OTPs as travel behaviour change programmes conducted in a workplace or education setting. We included published and unpublished randomised controlled trials and controlled before and after studies, where the measured outcomes included change in travel mode or health.
17 studies were included. One study directly measured health outcomes, and all studies measured change in travel mode. The overall methodological validity of studies was poor. The highest quality studies reported mixed effects on travel mode in the school setting. An isolated randomised controlled trial in a workplace suggests that reductions in car use are possible by people already contemplating or preparing for change to active travel.
Despite widespread implementation, there is insufficient evidence to determine the effectiveness of organisational travel plans for improving health or changing travel mode. Given the current lack of evidence, new OTP programmes should be implemented in the context of robustly-designed research studies, accounting for potential adverse effects such as child pedestrian injury. Cochrane systematic review methods used in partnerships between public health and transport planners can help achieve transport policy goals.
► Organisational travel plans (OTPs) aim to address health and sustainability goals in transport. ► Evidence for effectiveness of OTPs and other transport interventions are lacking. ► Our best practice systematic review found poor evidence for OTP effectiveness. ► Implementation of OTPs need to occur alongside robustly-designed epidemiologic studies. ► Best practice methods from epidemiology can help generate and assess such evidence.