Accessibility and built environment surrounding metro stations: a GISbased comparison of Naples line 1, Milan line 3 and London Jubilee line

This study fits into the research field of integrated land use and transport (LUT) planning. The use of urban policies based on this approach are considered an effective strategy to mitigate the negative externalities of car dependence, create more sustainable urban communities and advance economic competitiveness (Papa 2010; Suzuki et al. 2013). Research in this field has shown that urban environments with high densities, mixed and diverse land uses, located within an easy-walkable distance to transit stations yield a number of transport benefits such as reducing work trip distance, increasing the use of public transport and encouraging walking and cycling (Nahlik & Chester 2014). In the last decades, there has been a growth of interest in the concept of accessibility, with many studies published in the academic press discussing how to measure accessibility and how to use this concept for evaluating integrated LUT strategies (Curtis 2010; Coppola et al. 2014; Salas-Olmedo et al. 2016). Furthermore, land use and transport researchers interested in the analysis of the built environment and its association with mobility and accessibility have significally benefited from the increased availability of digital spatial data and the emergence of Geographic Information Systems (GIS) (Lin et al. 2014). The aim of this study is to develop a GISbased method for evaluating accessibility and the built environment surrounding metro stations and to apply this method to examining and comparing spatial accessibility to urban rail stations in three different urban contexts. To this aim, the paper review academic literature on integrated LUT planning and define a set of indicators able to describe urban environments that support transit use. The methodology is applied to the urban rail stations of the Naples Line 1, the Milan Line 3 and, the London Jubilee line. We select these lines according to the following criteria: i) they were opened in the same period; ii) they connect the city center with the outlying parts of the city and iii) they have a similar number of stations. Furthermore, we believe that the cities in which these lines operate represent three very different urban contests. In particular, we select the city of London as an example of a mega city with global importance; the city of Milan as an example of a major European city and the city of Naples as an example of southern European city. The reminder of the paper is organized as follow. The next section details data sources, indicator selection, and spatial accessibility calculation. The third section compares and discuss differences in the results for the three case studies. The last section summarizes the contributions of this paper and propose some suggestions on future research directions, offering some insights to this end.