The main research activities of the CAlCULUS project were related to accessibility analysis. For that reason, a comprehensive database was needed, covering route network and public transport data, distribution of population and potential destinations (e.g. job location or public services), among others. The collected private transport network data contained speed profiles, which enabled to analyse how accessibility evolves in time. The acquired data covers Spain and Poland. For the purpose of analyses of accessibility by public transport, detailed schedule-based data (so-called GTFS feeds – General Transport Feed Specification) were collected for more than twenty European cities. All GTFS datasets were supplemented by pedestrian networks, as well as population and job distribution data in fine spatial resolution.
Accessibility analyses conducted in CAlCULUS project covered three main topics:
The first one focused on assessing the impact of temporal resolution on the precision of public transport accessibility measurement. The research used the medium-size Polish city of Szczecin as a case study and included an evaluation of the impact of four sampling methods, four different public transport frequency scenarios, three types of accessibility measures (travel time to the nearest provider, cumulative opportunities measure and potential accessibility) and seven types of destinations ranging from high to low centrality of their spatial distribution. The study, conducted in international collaboration, was summarized in the paper published in the Journal of Transport Geography (2019).
The second branch of accessibility analysis took advantage of time-sensitive transport networks in order to delineate areas of low urban accessibility and to identify main transport-related accessibility restrictions in given areas. The novel approach enabled the preparation of several scenarios of accessibility levels in order to compare them against each other to assess the impact of particular factors on a decrease of accessibility level. These scenarios included trips made by private cars as well as public transport (an assessment of intermodal imbalance of accessibility), with the application of congested or free-flow speeds (an impact of congestion), trips made during peak and off-peak hours (an impact of frequency of public transport service) and, in the case of trips made by public transport, with and without waiting times (which permits evaluating the impact of public transport network design).
The third topic related to accessibility analysis aimed to evaluate the supply side of public transport at the European level, using open data (mostly GTFS) and open source solutions. The developed approach enables for straightforward evaluation of public transport service in a given area and easy comparison of results between different cities or functional urban areas (FUA), including international comparisons. Additionally, the CAlCULUS project aimed to investigate the interrelation between accessibility and mobility looking at the extent to which an increased mobility reinforced congestion and negatively influenced on accessibility to jobs.
The communication activities concentrated on the dissemination of the project results to professionals and the scientific community. The results of the CAlCULUS project were presented and discussed at several scientific conferences and workshops. Additionally, the general public was reached during the European Researchers’ Night events in Madrid, which was a perfect opportunity to attract a wider audience and raise their attention to transport planning and the importance of accessibility analysis, in particular in urban areas.
