Accessibility disparities

The goal of this project is to understand what drives and how to measure accessibility disparities. It is known that different transport modes create different accessibility conditions, but other issues like the time of the day, socio-demographic condition, as well as individual capability also can spur distinct accessibility disparities, which we intend to evaluate and demonstrate.

The project has at is core the use of available data (open data) and GIS and location inteligence analysis to properly evaluate and represent the disparities created by the existent land use and transport features of urban spaces, as well as to test different methodologies to measure it. Utlimately, the aim is to develop a tool to help guiding urban policies to diminish the existent accessibility disparities of cities.


Published articles:

Vale, David S., Fernando Ascensão, Nuno Raposo, e António P. Figueiredo (2017) “Comparing access for all: disability-induced accessibility disparity in Lisbon” Journal of Geographical Systems 19 (1), pp. 43-54.

Abstract: It is well known that individual impairments create disparities in the accessibility of individuals to opportunities, lengthening the distances or time needed to reach them or even completely impeding access. However, the accurate calculation and representation of these disparities remain a major challenge for urban and transportation planners. In this paper, we adopt the concept of accessibility disparity, originally applied to measure place accessibility by different modes of transport, to measure and represent the accessibility of individuals with physical disabilities compared to those without disabilities. We use spatial network analysis to calculate spatial connectivity and the accessibility of Lisbon’s city center, revealing what we define as ‘disability-induced accessibility disparity’. Our results reveal not only the locations responsible for reduced accessibility, i.e., barriers and/or deterrents to movement, but also how much any given disparity reduces the accessibility of an individual, allowing the use of this methodology by planners to identify critical areas and to design inclusive public spaces.


Viana, C. M., & Vale, D. S. (2017). Disparidade de acessibilidade multimodal aos serviços de saúde em Lisboa : uma análise espacial em SIG. Proceedings do XI Congresso da Geografia Portuguesa, pp. 187–191.

Abstract: A acessibilidade aos serviços de saúde é reconhecida como um importante elemento de promoção da saúde. Na maioria da literatura existente, o foco incide na acessibilidade por automóvel, ignorando a influência que o modo de transporte colectivo tem nas condições de acessibilidade. Neste estudo, medimos a acessibilidade aos serviços de saúde de Lisboa – farmácias (n=263), hospitais (n=24) e centros de saúde (n=45) – através de medidas de oportunidades acumuladas, considerando três modos distintos – a pé, carro e transporte colectivo – e calculámos a disparidade de acessibilidade entre modos. No cálculo do tempo de viagem consideraram-se diferentes limites máximos para cada modo: 10, 20 e 30 minutos. Os tempos de viagem em transporte colectivo foram obtidos através de dados General Transit Feed Specification, considerando a hora de ponta matinal (8-9h). Os resultados demonstram o evidente impacto que o modo de viagem tem na acessibilidade aos serviços de saúde, especialmente no caso de acesso a farmácias e a centros de saúde.

Feel free to contact us if you want a copy of any of our published papers.