Cities Research Seminar Series: Accessibility Across Transport Modes and Residential Developments in Nairobi

A seminar lead by Kayleigh Campbell of the World Bank on accessibility across mobility modes in cities of low-income countries. A key goal of urban transportation planning is to provide people with access to a greater number of economic and social opportunities, which depends on both the transport and land use systems. Access and related accessibility measures are gaining attention globally, yet there are few studies that measure accessibility in cities in low-income countries and even fewer that incorporate semi-formal bus systems, also called paratransit. This research draws on rich datasets available for Nairobi, Kenya to measure and visualize mobility and accessibility for walking, paratransit, and driving and to compare levels of access to health facilities across different types of residential development. Because car ownership rates are low and the majority of trips taken are by walking or paratransit, it is important to understand how the relationships between transportation, land use, and housing may contribute to spatial inequalities.

As expected, we find that accessibility is highest for driving, then paratransit, then walking and there are high levels of access to health facilities near the Central Business District (CBD) for all modes. The difference between driving and paratransit accessibility is much smaller than the difference between paratransit and walking, indicating that paratransit may be providing access in an efficient way. We also find significant variation in accessibility across residential developments with the wealthiest areas having very low levels of access for each mode and the poor areas having comparatively better walking access to health facilities. Controlling for distance from the CBD, two kinds of residential development stand out: large homes in gated communities, which have very low access for all three modes, and the residential type with a medium low level of income, characterized in part by tenement apartment buildings, which has significantly higher access than other residential types. Understanding how mobility and accessibility vary spatially across modes, as well as how they vary across residential developments and income is important for raising questions about whom the city is currently serving and for designing policies that provide access for all.

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Speaker: Kayleigh Campbell

Kayleigh Campbell is an Operations Officer at the World Bank in the Development Impact Evaluation (DIME) unit in the Development Research Group. She manages operations for the ieConnect for Impact program of impact evaluations in transport. The goal of the ieConnect program is to generate data and evidence on the impact of transport policies and investments, including indirect benefits, at a sufficient scale to substantially improve the evidence-base for policy making.

The portfolio includes 30 evaluations in 19 different countries across the themes of urban mobility, road safety, and transport corridors. Kayleigh's research uses quantitative methods to explore how transport shapes cities and the lives of people in cities. A common theme throughout her work has been the importance of a multi-modal focus for understanding the social and environmental impacts of transportation. This has ranged from measuring the impact that opening a bikesharing system had on bus transit ridership in New York City; to comparing the variation in present-day carbon dioxide emissions across U.S. cities built around rail transit versus cities built around the automobile; to exploring how accessibility varies across transport modes, residential developments, and income groups in Nairobi, Kenya. She holds a Ph.D. and M.A. in Sustainable Development and a B.A. in Economics from Columbia University.

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