Given that the safety impacts of traffic management measures, including their effect on traffic speed, have been reasonably well-established, we wanted to explore the potential impact of such treatments on mode choice and travel behaviour such as travel patterns. We created the term 'slow zone' treatment or programme to generically describe the aim of any programme that modified the physical road environment in such a way it would moderate driver behaviour, slow vehicle traffic, and/or improve the environment of the neighbourhood.
We adopted an evaluability assessment framework as the methodological approach for this research project. Evaluability assessment is a systematic process that helps identify whether a planned programme evaluation is justified, feasible and likely to provide useful information. In the first stage of an assessment, one output is an evidence-based logic model. In completing the tasks for this stage, we found the evidence review did not allow us to develop a comprehensive logic model as planned, because we could not clearly identify slow zone programme 'best practice(s)' for facilitating mode shifts or changes in transport mode use. Hence, we developed less detailed guidance for a monitoring framework to help collect appropriate outcome and impact data.