Africa is rapidly urbanising and motorising, complicating its existing urban transport impacts such as high road traffic injuries, air pollution, and decreasing physical activity derived from walking and cycling. This situation highlights a need to develop healthy and sustainable urban transport systems on the continent. Modelling studies can help unpack the effects of urban transport plans and policies, thus facilitating evidence generation for policymaking. However, the use of modelling approaches in Africa is limited. This thesis aimed to increase understanding of the health impacts of changes in African urban transport systems through modelling.

I started by exploring travel and physical activity behaviours and their data sources in selected African cities to elicit the context and address some challenges related to model data inputs from surveys. Secondly, I explored health integration in urban transport policies to gauge the transport sector’s commitment to supporting health goals and the range of meaningful modelling scenarios for engaging stakeholders in the African context. Thirdly, I reviewed modelling studies on transport health impacts to synthesise modelling approaches and guide model selection and adaptation. Finally, I modelled urban transport health impacts in five African cities for four scenarios: cycling, bus, car and motorcycle. Each scenario represented a 5% increase in the chosen transport mode.

Surveys using travel and time-use diaries were valuable sources of travel behaviour data. Travel behaviour case studies from four cities, Nairobi and Kisumu (Kenya), Yaoundé (Cameroon), and Accra (Ghana), showed a wide variation of immobility and daily travel duration across cities, with walking as the primary mode and privately owned small-capacity public transport as the second. Motorcycles were also an essential component of public transportation in some cities. The physical activity case study from Accra showed high levels of background physical activity with a substantial contribution from transport. However, there was a significant disagreement between the Global Physical Activity Questionnaire and travel diary physical activity measurements, signalling precaution when using these crucial data sources for modelling. The policy analysis from Cameroon showed the integration of physical activity and non-communicable diseases in the policies of some sectors but not the transport sector, suggesting that modellers need simple illustrative scenarios to pitch transport health benefits to the naive transport sector. The systematic review identified several models in different contexts and various scenarios. Studies on the application of models in low-and middle-income countries were scarce, but overall review findings could guide transport health impact modelling in African cities. The modelling study in five African cities showed reduced adverse outcomes from shifts towards cycling and bus for public transport, mainly from gains in physical activity and reduction in air pollution, as road traffic fatalities were significant for the cycling scenario in some cities. Comparatively, car and motorcycle scenarios showed increased adverse outcomes from air pollution and physical inactivity, with additional road injuries for the motorcycle scenario across cities.

The thesis sheds light on using relatively complex tools to elicit the health impacts of changes in urban transport in contexts with limited data, making a case for transport policies that favour active travel even in settings where active travel is already prevalent. It provides cross-city results, which help cities compare the effects of similar policies in different contexts, supporting collaboration amongst cities and increasing opportunities to learn from one another. Additionally, the thesis highlights our limited understanding of travel behaviour from available surveys and caveats in model adaptation as priority areas for future research.