In transport and urban research, accessibility has long been used to gauge inequalities and inequities in employment, education, health, green spaces, among other. Space-time accessibility measures have seen significant development since they were first proposed, and yet, they can make additional contributions to transportation justice if its processes and practices are attuned to the experiences and knowledge of diverse groups and individuals. In this paper a transdisciplinary approach to space-time accessibility measurements which has been developed with a collective of low-income women in Colombia is introduced, and an example of its application is developed. Through the example of how accessibility measures change with the location of publicly available child-care, we show how land-use and transport policy are intimately related and have profound implications on daily activities of low-income women in the Global South. We argue that the co-production practice of our work helps reduce the epistemic injustices embedded in much of transport research today, and conclude that by following the general principles outlined, researchers will be able to foster new ways to understand the city and its inequalities and reflect on ways to reduce them.