Measuring the permeability of border sections involves looking simultaneously at demand for, and supply of, cross-border public transport services (CBPT). CBPT supply is defined by the number of services, as displayed in the web viewer (Link) and measures CBPT service availability. The demand side is measured by population density and development. Demand for CBPT services may be high if:
- population density is high on both sides of the border, e.g. in agglomeration areas or twin cities;
- population density is very unbalanced, e.g. in the case of agglomerations on one side and rural areas on the other side;
- the population has been significantly growing in the border area in recent years.
Calculation of the transport permeability index puts CBPT supply and demand in relation to one another. The higher the index, the better is the match between supply and demand, and vice versa. Border sections with a particularly low index may be those with the highest demand for additional CBPT. The analysis of permeability highlights:
- high permeability for border sections in the Alps and maritime borders such as between Germany and Denmark, Denmark and Sweden, and Italy and France;
- that despite the generally high permeability between Benelux countries, France and Germany, and Germany and Switzerland, there are sections that would benefit from additional services;
- there is generally low permeability for longer border area in Scandinavia, the Baltic States, East European countries, the Pyrenees and the Portuguese-Spanish border;
- some of these non-permeable border sections have no specific demand for CBPT as a lack of services coincides with a lack of demand.
However, if services were increased where latent demand was identified, the proportion of non-permeable borders could be significantly reduced.
Further results on obstacles and solutions to CBPT and governance arrangements will be shared soon.