Inclusive intervention design for vulnerable road users: Applying co-design and behaviour change model in Bangladesh

In developing countries, it is debatable whether poor design of facilities or violation of traffic rules by road users is the leading cause of pedestrian injuries and deaths. Professionals, pedestrians and drivers tend to blame each other. Shared responsibility for road safety is crucial for protecting vulnerable road users such as commuting students and workers who face higher injury risks while crossing highways. While the Safe System approach emphasises authorities’ responsibility for safe facilities, understanding user needs and promoting behaviour change remain underexplored. This study investigates the current design practices in Bangladesh. It compares the impact of conventional design with co-design on intervention quality and examines the further benefits of integrating a behaviour change model ‘COM-B’.

Local road agency professionals applied the design process and suggested interventions at four highway sites. Subsequently, four focus group sessions were conducted with students and workers, followed by four design workshops. In each workshop, participants were randomly assigned to two design groups (without and with the application of the behaviour change model), where they designed interventions facilitated by professionals. Lastly, perception ratings of stakeholders and safety assessments by four experts were conducted to evaluate the efficacy of all interventions.

The findings highlight major usability problems in conventional designs, while co-designed interventions demonstrate clear improvements. Notably, integrating a behaviour change model further enhances effectiveness. Stakeholder interviews reveal that co-design fosters shared responsibility and addresses the blame culture. The co-design approach and application of the behaviour change model can address design flaws and promote the proper use of facilities.