This indicator shows the volume and modal split of passenger transport in Slovenia and the modal split of passenger transport in EU countries. The data for Slovenia presents the development of passenger kilometres in road passenger transport by cars, public road passenger transport, urban public passenger transport and domestic rail passenger transport and the development of the number of passengers by mode of transport in the period 1990-2014; the data for selected European countries presents the modal split in 2013.

The volume and modal split of passenger transport is expressed in passenger kilometres. A passenger kilometre (pkm) is the product of the number of passengers multiplied by the total distance they travelled. The volume of passenger transport is expressed with a sum of all travelled passenger kilometres in a certain area over a certain period of time, while the modal split is expressed as the share of passenger kilometres by mode of transport (road, rail, sea or air).

The volume of land passenger transport is also expressed in relation to gross domestic product (GDP) in Slovenia and the EU-28, which indicates potential connections between transport growth and economic growth. From an environmental perspective, the decoupling of these two parameters is desirable, with a view that transport growth, which negatively affects the environment, should be slower than economic growth. The relationship is expressed by a decoupling indicator: a ratio between transport and economy growth rates. The data for Slovenia and the EU-28 countries are presented by indices (the year 2003 = 100) for the period 2003–2013.

The volume and modal split of passenger transport is an important indicator of the functioning of the transport system, indicating the extent and modes of travel by residents of a certain country. Selection of a transport mode is important due to the differences in environmental, economic and social effectiveness of individual transport modes and, consequently, the different impacts of their use.

On the basis of existing analyses and indirect data, such as decreasing demand for public passenger transport, increasing use of motor vehicles, energy consumption in transport and overloading of road infrastructure, it can be assumed that the volume of passenger transport is developing in an environmentally problematic direction, mostly due to a longer period of growth in the use of passenger cars and airplanes.

Rapid growth in the use of passenger cars in Slovenia as well as in other countries is one of the greatest environmental challenges. According to Eurostat, 25.2 billion passenger kilometres were travelled by cars in 2013 on Slovenian state roads, which is slightly less than at the peak in 2009 (slightly below 26 billion passenger kilometres) and 25% more than in 2000 (20.3 billion pkm). The figures for 2011, 2012 and 2013 are only estimates. Other modes of land passenger transport lag behind passenger cars in volume as well as in growth. The situation is most concerning in public road passenger transport, which includes public bus transport carried out by Slovenian bus operating companies. In 2013, these companies performed 3.3 billion passenger kilometres, which is 46% less than in 1990 and 6% less than in 2000. After a drastic drop in the 1990s, domestic rail passenger transport has been gradually increasing. In 2013, 626 million passenger kilometres were travelled, which is 45% less than in 1990 and 2% more than in 2000.

In the recent decade, the number of passengers on inter-city bus transport dropped by 53%, and on city buses by 36%. In 2014, 26.7 million passengers were carried by inter-city buses and 47.5 by city buses. In the same year, 14 million passengers were carried by domestic railways. After Slovenia joined the EU and became a Schengen member, the number of airline passengers grew rapidly. In 2008 1.7 million passengers were carried in and out of Slovenia by airlines. In 2011, a sharp increase in the number of passengers in maritime transport took place (133,000 passengers compared to 71,000 in 2010). In 2014, however, the number of maritime passengers dropped to 87,000 again. After 2008 and 2009, a considerable drop in the number of passengers took place in all modes of transport, which was probably a consequence of the global economic recession. The data from 2012 onwards is not entirely comparable with data for previous years due to modifications in methodology.

In EU countries, the use of passenger cars prevails in passenger transport. In 2013, more than 83% of all passenger kilometres were travelled by cars in the EU-28. Despite their low share in passenger transport, a growing demand for railway and bus transport has been observed in the EU, especially in the most developed EU Member States. According to the data provided by the European Environment Agency (EEA), the use of passenger cars in Slovenia was more than 86% in 2013, which ranks Slovenia above the European average, i.e. among the countries where most passenger transport is carried out by passenger cars. Demand for public passenger transport has been decreasing since 2008, particularly due to negative effects of the global economic crisis.

In Slovenia, the growth of transport stopped in 2008 due to the recession. Since then, decoupling between transport growth and economic growth has been stable and environmentally favourable. Passenger transport in Slovenia started increasing after Slovenia joined the EU. The number of passenger kilometres peaked in 2009, increasing by 14% from 2003. During the economic recession, passenger transport declined by approximately 2% until 2013. The GDP grew rapidly until 2008, after which it stagnated during the economic crisis. The trend of passenger transport in the EU-28 is similar as in Slovenia. It grew by 14% in the period 2003–2009. After a longer period of GDP growth, its decline was recorded in 2009 and 2010. Decoupling has been observed in the EU-28 countries as well. In the period 2003–2009, passenger kilometres in the EU-28 increased by 4%, while since then they have stagnated. After a slight decline in 2009, a 9% increase in the GDP was recorded by 2013.

Many indicators (motorisation development, investments in infrastructure, changing settlement patterns, non-competitiveness of public passenger transport) show that Slovenia should adopt measures to reduce the use of cars in passenger transport. The state as well as local communities, having a capacity to change the travel habits of inhabitants, could contribute to this end. Thanks to EU funds available for the preparation of integrated transport strategies, the greatest changes are expected at the level of municipalities or cities that will develop the strategies.