A Data Envelopment Analysis approach for accessibility measures: Simulating operational enhancement scenarios for railway across Europe

Introduction As well known, infrastructure endowment influences competitiveness of a region since the characteristics of a transport system in terms of capacity, connectivity, speeds, etc. determine the advantages/disadvantages of an area compared to other locations. This article attempts to investigate the potential impacts on rail accessibility across Europe when different possible operational enhancement scenarios are simulated. Methods The simulations are carried out by means of a combination of the TRANSTOOLS rail network and Traffic Analyst, the post-processing analyses are implemented in Matlab and the results for each zone (at NUTS3 level) are reported both in tabular form and in easy-to-read ArcGIS maps. Several accessibility measures are evaluated including two Data Envelopment Analysis (DEA) approaches aiming to construct a composite index for embracing all the complementary information provided by 'partial' accessibility sub-indicators; to better evaluate and understand the results either sensitivity and robustness analyses are performed for both the aggregate indicators. Results The outcomes provide insight into where major benefits in terms of accessibility can be expected; in particular the current infrastructure endowment already benefits many regions but improvements in speed could still increase significantly rail accessibility across Europe (mainly outside the core area as in Poland, Bulgaria, Romania, Slovakia, etc.). Furthermore both the proposed global indexes, although associating different 'endogenous' weights to the various sub-indicators, appear to be worthy and robust against uniform random noise. Conclusions Ultimately the results provide information useful for the prioritization of investment needs; moreover even if the interpretation of the partial accessibility indicators is clear and useful for policy-makers, the evaluation of a composite measure could allow planners not only to compare or fully rank the level of accessibility for different regions but even to control for eventual confusing and/or incomplete results that may appear when using only a partial approach.