Dostępność potencjałowa regionów w Europie - zasięg przestrzenny, długość podróży i efekt granicy (EU-ROAD-ACC) = Potential accessibility of European regions : spatial reach, travel duration and the border effect (EU-ROAD-ACC)
Authors: Rosik Piotr , Komornicki Tomasz , Goliszek Sławomir , Duma Patryk 
Published: October 2020

Accessibility ranks among the most frequently investigated research topics in transport geog-raphy. Studies involving accessibility components focus on various spatial scales ranging from local, to regional, national and international. In Europe, especially in its central-eastern part, Community-funded infrastructural projects, primarily concentrated along the Trans-European Transport Network (TEN-T) corridors, combined with geopolitical change and rapid economic growth have resulted in considerable change in accessibility by road, and this has drawn strong interest from researchers who have engaged in research on accessibility at both national and international levels. In the past there was no accessibility model available which prevented high granularity studies (NUTS3 level) of changes in accessibility for trips over various distances in Europe. Researchers were not in a position to conduct a strand of accessibility research with potentially important benefits at a continental and country-to-country scale. Any studies published always excluded some accessibility dimensions and often limited themselves to just the European Union. Meanwhile, during the previous decade, European borders saw rapid change, in par-ticular within the Schengen zone. The zone’s functioning philosophy was altered by a series of events, including the refugee crisis of 2015, Brexit, although more lightly, and most of all the COVID-19 pandemic of 2020. These events changed the accessibilities of the continent’s regions and for many this has meant a rapid increase in their peripherality. Clearly, this new situation calls for in-depth research by way of simulation, which is facilitated by the potential model used in this volume. Our volume summarises the project “EU-ROAD-ACC (EUropean ROAD ACCessibility)”, financed by the Polish National Science Centre (UMO-2014/13/B/HS4/03397). The main objective of the EU-ROAD-ACC Project was to propose a research methodology to calculate indicators of transport accessibility using the potential model, including method-ologies to: 1. Calculate accessibility at various spatial scales, including European and national; 2. Determine the role of borders, including the border effect, by looking at political barriers and changes in Europe over the previous decade; 3. Estimate accessibility for both long and short trips on the basis of differentiating between CATCH-times along the exponential dis-tance decay function; 4. Calculate accessibility to population (population potential) and to GDP (economic potential), including in the context of the relationships between the two potentials (potential quotient). As a supplementary methodological objective, the study also looks to flesh out the method-ology for the calculation of what is known as the potential quotient as a spatial dimension of the variability of GDP per capita and to identify the sensitivity of the European Union’s regions to the closure of the internal UE-27 borders due to the occurrence of black swans, such as the COVID-19pandemic in March 2020. 111The analysis uses the 2015 Europe-wide road network proposed by IGiPZ PAN that allows a car trip between any pair of the 1621 transport regions defined across the continent. The road network was based on the network database sourced with OpenStreetMap (OSM), which is estimated to be up to date to about the year 2015. The overall number of 1337 transport regions in the European Union was defined at NUTS 3 level. The study has come to the following conclusions. National borders have a negative impact on accessibility when they require the car to stop, typically for a border check. In general, at the scale of Europe as a whole and with few exceptions, the basic distinction between a border with or without border control is between borders within and outside the Schengen group. Since the fall of the Iron Curtain, border restrictions across Europe have gradually diminished, while the European Union and the Schengen group have expanded by including new members. In the second decade of the 21st century, however, several events worked together to slow this process down. These events included the refugee crisis, the annexation of Crimea and the related war-fare in eastern Ukraine, Brexit, and the COVID-19 pandemic. The experience of closing the borders in the spring of 2020 (COVID-19 epidemic) shows that political borders remain the most convenient place to restrict the movement of people and goods whenever such restrictions may become necessary. While virtually all countries closed their national borders, only very few chose to restrict movement internally between their own administrative units. This means that the location vis-à-vis borders may continue to have a very strong impact on the positioning of units, whether cities or regions, in terms of their transport accessibility, and, as a consequence, may affect their potential to reap the rewards of proximity to economically or demographically more attractive regions. One example of such an impact is provided by those German regions that have been cut off from labour in Poland and Czechia. In this context the results on the potential quotient and on discontinuity belts, described below, may be perceived equally as identifying faster-growth “opportunity” zones and as sensitive zones that are dependent on regions across a border that in certain conditions may be shut. Conclusions: MAX variant accessibility (fully permeable European borders) In the maximum accessibility variant the borders do not hinder free movement of people and goods. This means that there is no waiting at the border. In these circumstances, the key fac-tor for accessibility is the quality of the road infrastructure and the distribution of masses, in this case of the population and the GDP. The results vary depending on the adopted CATCH-time values. In short trips (CATCH-time of 30 minutes) agglomerations and the largest cities clearly stand out while the core-periphery distribution of accessibility is more peaky with dom-inants for the largest cities and agglomerations. As the travel time grows and the CATCH-times increase, the peakiness of the distribution is smoothed out and assumes an increasingly con-centric pattern with the European core (Blue Banana) spreading from south-eastern England, to Benelux, north-eastern France, to Germany, Austria, Switzerland and to northern Italy. The European east is an extreme periphery with two exceptions of the areas around Moscow and Istanbul. This extreme periphery area becomes even larger when nominal GDP is used to meas-ure the attractiveness of the destination. Beyond Eastern Europe and eastern Turkey, extreme peripheries also include Mediterranean islands, Iceland and the northern Nordic countries. In the case of accessibility to population such extreme peripheries are limited to certain areas in 112Russia and eastern Turkey, but in the Nordic countries are larger than their counterparts for GDP and “creep up” towards Stockholm and Oslo.Conclusions – MIN variant accessibility (non-permeable European borders)Assuming no permeability of the borders, where each country is looked at separately with-out the option of crossing from one to another, the demographic potential (accessibility to population) and economic potential (accessibility to GDP) are calculated only for domestic des-tinations and their attractiveness. This would suggest greater accessibility levels in the country’s centre, or around large cities or their agglomerations, while lower levels near the borders or in sparsely populated areas. Motorways and expressways (i.e. the condition of the road infrastruc-ture) also play a part. In short trips (CATCH-time of 30 minutes), cores with better accessibility are clearly visible in the capital cities (in monocentric countries), or in exceptional cases, at two poles (e.g. in Poland in Warsaw and Upper Silesia). As road trips become longer, so any peaks become less visible and with truly long trips they only remain visible in Russia (Moscow) and Turkey (Istanbul). On the other hand, extreme peripheries in short trips are visible in such areas as the Spanish-Portuguese frontier and the boundary between Mecklenburg-Vorpommern in Germany and Zachodniopomorskie Voivodeship in Poland. For long trips, extreme peripheries are limited to just some Mediterranean islands, Northern Ireland, western Scotland, the north-ern fringes of Scandinavia and the north and east of European Russia. In terms of access to GDP, these areas are joined by eastern Turkey as an extreme periphery for long trips. Conclusions – European vs. national potential. TypologyComparison of the European core and national core areas (understood for the purpose of this section of the study as areas with above-average European or national accessibility, respec-tively), for various CATCH-time values offers interesting results. As CATCH-times increase, the core areas expand both at the European and national levels. This is explained by the potential model’s specific characteristic that equalises disparities of potential as trip durations increase, regardless of the spatial scale of the study. Since the European economic centre of gravity is located to the west of its demographic centre of gravity, this pattern is also true in the case of the European core calculated using the potential model. It could be predicted that should income convergence continue in this part of Europe, it would contribute to an equalisation in the areas of the population and economic cores at the European level. Conclusions – the impact of the COVID-19 pandemic and the related closure of internal EU borders on accessibility The sudden drop in accessibility up to and in excess of 95 per cent for long trips could be regarded as an additional factor, alongside the economic crisis, compounding the economic problems of regions in the spring of 2020. This phenomenon has a strong territorial dimension to it and constitutes a factor in a place-based policy. It seems very important to assess the impact of the diminished border permeability due to the COVID-19 pandemic on the socio-economic processes and on territorial cohesion. The spatial pattern of regions facing peripheralisation, determined using short trip accessibility losses, is a very useful tool for the identification of 113zones where a serious crisis looms over local work commuting across the border. Despite decades of support for cross border cooperation, no cross border functional areas have devel-oped to a point where they would be the subject of mobility policies at a time of crisis. The threat of peripheralisation mainly affects parts of countries that are located close to the EU’s demographic and economic core. This is particularly true for long trips. The effect is mainly a consequence of the distribution of the population across the continent, but in some countries it is also exacerbated by other factors, such as the national settlement network and the road network pattern, especially the pattern of the TEN-T network. Conclusions – potential quotientThe potential quotient proved to be a promising tool in the analysis of interregional differ-ences both at the overall European and national scales. A surplus of economic potential over demographic potential may be explained by geographical proximity and the existence of qual-ity interregional connections providing links with economic hubs. At the international level, proximity to the European core is the number one factor affecting the outcome, while in border areas the strongest role is played by proximity to a foreign country that has a considerably different level of income. As the space decay curve is smoothed out and CATCH-times grow, the spatial distribution of the potential quotient increasingly flattens out and interregional differences disappear at both the overall European and domestic level. The bundle of curves linking potential quotient levels between regions within a single country for different CATCH-times resembles a tornado. An extension of travel time to the point of very long trips leads to regional convergence in potential quotient values, again for both the entire system, such as a continent, and individual subsystems, i.e. countries. When the trips become very long, i.e. with CATCH-times counted in days, weeks or months, time ceases to matter and all inhabitants of the European continent are virtually equal in terms of the division of income. Naturally, owing to the shape of the model, there will remain minimal differences between the inhabitants of the peripheries and the centre of a system, but for very long trips they are basically immaterial. Depending on the needs of a given spatial scale (i.e. European vs. national, and the trip moti-vation selected, i.e. work commuting vs. migrations), the potential quotient may prove a useful measure, especially compared to GDP per capita, of differentiation between core and peripheral areas and can be used to develop a concept of internal peripheries within Europe. Conclusions for spatial policyThe results obtained confirm the significance of measures taken in many countries and at the European Union level which are intended to retain a maximum possible degree of polycentricity in spatial structures. The priority is to maintain economic polycentricity (GDP), which generally tends to be lower than demographic polycentricity at both the continental and national levels. In this context, spatial policies should aim first of all to equalise the demo-graphic and economic potentials (by reducing potential quotient for long trips beyond daily mobility), rather than creating new poles of growth (a difficult task in a market economy any-way). At the European scale, the strengthening of the polycentric pattern has its geopolitical dimensions. The inscription of polycentricity as a basic objective of European spatial policy in its subsequent territorial agendas has been confirmed by the results of this study. One of their 114premises is to counter the development and existence of peripheries between the European core and the two nearby poles located in Istanbul and Moscow. While currently the latter two pos-sess limited significance, the political and military power wielded by their respective countries could potentially contribute to their growing up as alternative centres of gravity in times of crisis in the European Union. In such circumstances, the European Union’s spatial policy aims to strengthen economic poles existing within broadly understood Central Europe. Another important area is linked to border zones, especially ones with clear “discontinuity belts”. For decades, the European Union provided extensive support to cross-border cooperation over the internal borders and sometimes also over the external EU border. This has led to the develop-ment of large areas with integrated labour and service markets, including around Luxembourg, on the Polish-German border, and around the convergence point of the Austrian, Hungarian and Slovakian borders. As cross border transport infrastructure expanded, so did these areas themselves. For all of these developments, however, the barrier of institutional integration has not been successfully overcome. Indeed, the support has been fragmentary in nature, partly because of the nature of the INTERREG structural programmes, and it has not favoured the establishing of functional cross border regions. Their lack was powerfully revealed upon the closure of the national borders in 2020, when the previously created cross border labour mar-kets were allowed to rupture as the respective countries found insufficient reason to isolate them as a whole under mobility containment measures during the epidemic. Conclusions for transport policyThe results of the study confirmed that the European space required a diversified transport policy. A system of priorities for investment projects should rest on the following criteria: a) objectives to be achieved (e.g. shortening of long trips vs. upgrading transport in integrated functional areas), b) geographical location, and c) the condition of the existing infrastructure. It seems crucial for the objectives to be reconciled through correct integration of the European (TEN-T), the national and even the regional infrastructures. The current focus on transconti-nental projects has contributed to the phenomenon of internal peripheries (both European and national) thus increasing certain regions’ exposure to problems caused by events, such as the closure of national borders in 2020, for example including stretches of motorways that do not provide sufficient access to the relevant border areas. What seems particularly important would be to place a selection of precisely located and carefully thought out transport projects within the discontinuity belts identified. These could support spatial integration without the need for intensified migration. Methodological conclusions with a European level accessibility model. Potential for further researchThe potential model offers numerous advantages. One of them is its applicability at various spatial scales, from the local, to regional, national, European (continental) and to a global scale. This volume proposes a potential model of road accessibility for 1621 regions across the whole of Europe and, as such, is the first attempt to analyse the issue at the scale of the entire continent. Indeed, in existing research from Western Europe (including the projects and publications of 115the Spiekermann and Wegener company from Dortmund, Germany), the focus has mainly been on monitoring accessibility changes within the European Union. Beyond this approach, there are other interesting phenomena requiring static analysis, such as a comparison of inter-national and national accessibilities, including with the use of the potential quotient method. This study “squeezes” most of what was potentially available in static analysis of accessibility in a single transport mode. There are, however, still possibilities to expand the static dimension of the model. One such possibility is to look for a European centre of potential by adopting various space decay curves, various function forms and various β parameters and CATCH-time values (for the exponential function). Another possible way of building on the European potential model in the static approach would clearly be to introduce border-waiting times. Indeed, this had been an ambition of the authors, but due to the unavailability of uniform databases and a great deal of variability in the border waiting times outside of the Schengen zone, this research idea was not taken forward. Should such a database become available, one could attempt to sim-ulate the impact of the reduction in waiting time at selected stretches of the border on improved accessibility in border regions or entire countries. Simulations performed in this study were of the 0/1 type and so produced two extreme outcomes, i.e. either full permeability or impervious borders. This assumption made it impossible to simulate the influence of full border closure in the European Union, such as the one introduced in response to the COVID-19 pandemic. The proposed model, however, can be successfully applied to the analysis of positive effects of grow-ing accessibility, e.g. for selected infrastructure projects, such as the TEN-T road corridors, or such future projects spanning many countries, as the Via Carpatia. However, to successfully analyse infrastructure projects, especially large ones that take decades to complete, it would require a full monitoring system, i.e. both of socio-economic data (GDP, population) and infra-structural data (change due to investment in all the countries involved in the study, at least for the largest motorway and expressway projects.