Measuring the Sustainable Development Goal (SDG) Transport Target and Accessibility of Nairobi’s Matatus

The urban Sustainable Development Goal (SDG) includes the target to provide “access to safe, affordable, accessible and sustainable transport systems for all” by 2030. However, debate exists around the best indicator to measure this target, and few actual measurements exist. This is in part because basic transit data are missing from many of the world’s cities, including in Africa where popular or “informal” systems dominate. This paper explores how to make progress in measuring indicators for the SDG transport target using Nairobi’s minibus system, matatus, as a case study. We partially measure the SDG indicator for the city as currently defined by the UN and then compare the SDG measurement to a location-based accessibility indicator that incorporates income data, travel times, and land-use considerations for Nairobi’s highly monocentric spatial urban form. We show that although the SDG analysis suggests generally favorable transit coverage, it also points to underlying transport inequalities for low-income residents. The more fine-grained location-based accessibility analysis reveals rapidly decreasing accessibility to opportunities as distance increases from the city’s central business district. This accessibility-based analysis further highlights income-based transport inequalities, identifying opportunities for improving integrated transport for residents living on the city’s near and far peripheries. Improving non-motorized transport access for those living in low-income areas with high access potential would also be important to improve access. We recommend that cities start using open-source software and open data to measure a variety of indicators needed for data-driven policy, to meet SDG 11.2 and go further to improve access to opportunities for all residents.

Transport Inequalities for Log-concave Measures, Quantitative Forms, and Applications

We review some simple techniques based on monotonemass transport that allow us to obtain transport-type inequalities for any log-concave probability measures, and formore generalmeasures as well. We discuss quantitative forms of these inequalities, with application to the Brascamp-Lieb variance inequality.