Measure of urban accessibility provided by transport services in Turin: a traveller perspective through a mobility survey

Accessibility is a fundamental aspect for cities and a good degree of connection among different urban areas can be reached by smoothing the travel experience, through the efficient use of public and private transport modes. On the whole, a variety of methods has been developed for measuring accessibility, based on different kinds of dataset and using various types of metrics and indices. In this paper, accessibility is analysed focusing on travel times, as perceived by travellers, the measured travel distances and the average speed, derived from these two attributes, to connect various areas of the city. The methodology developed in the paper is tested on a real dataset for the city of Turin (Italy). This comes to be a proper test site through the availability of citizens’ mobility data collected through a travel diary survey proposed in three waves in 2016 and 2017. Such dataset provides useful information to measure the accessibility of different areas of the city. In this way, it is possible to measure how the zones of a city are differently connected, with a strong dependence on the available transport modes and their quality. Results are compared using both active and passive accessibility indicators, to assess the difference between travellers’ perception and the scheduled service for the public transport network. The evaluation proposed can provide useful information to estimate the accessibility at city level and map the zones for their ranking assessment.