The volume of passenger transport demand has been increasing in Slovenia for several decades. Above all the volume of two most unsustainable modes – passenger cars and air transport (especially after 2002). The growth stopped after the economic recession in 2008 but intensified again after 2014. In 2020 and 2021 the pandemics caused another, steep decline. Trend of the public transport modes has been declining for decades, especially the proportion of intercity bus services.

Road goods transport has been growing sharply since Slovenia joined the EU, as the volume of tonne-kilometres of the Slovenian transport carriers increased by more than 2,5 times in the period 2004-2019. The growth of freight transport and transit in Slovenia has been constant in road, rail and maritime transport since independence, despite intermediate economic problems in the EU during the recession 2008-2014. The exception is air freight transport, which has stagnated for years after a sharp decline in 2008.

In the first decade of this century, Slovenia focused the majority of its investments in the road network, especially on the construction of the motorway. Investments in railways have been neglected and therefore, uncompetitive with the road transport. After 2011, this trend is changing, although the total volume of investments in transport infrastructure has decreased significantly since 2008. Since 2010, Slovenia has been allocating a larger share of funds to the modernization and upgrading of the railway network.

Energy consumption in transport has been declining slightly in recent years. This is due to combination of lower domestic vehicle consumption as well as lower sales to foreign vehicles. Most of the energy is used in road transport. Consumption of diesel fuel in road transport is increasing.

The estimated value of external transport costs in 2021 is approximately 2.4 billion euros, accounting for 4.6% of Slovenia's GDP. The majority (99%) of these costs are attributed to road traffic, while only 1% is attributed to rail traffic. Two-thirds of external costs arise from passenger traffic, with the remaining one-third from freight traffic. Notably, a third of the external costs of transport are associated with traffic accidents, followed by costs related to congestion (20%), climate change (18%), air pollution (16%), damage to habitats (7%), and noise (6%).

Both the residents of the EU-27 countries and the residents of Slovenia are only partially aware of the problem of increasing transport and its consequences for the environment and health. Public awareness of the impact of transport on the environment is still relatively low, although the differences between European countries are considerable. People's awareness of the environmental problems of transport does not automatically lead to changing their travel habits, even though this would contribute to their better health.

Data on air pollution shows that Slovenian cities are over-polluted with NO₂ and PM₁₀. Transport is one of the main causes of this pollution. Air quality in Slovenian cities improved during the economic recession after 2008, and after 2016 the NO₂ pollution became worse again.

In the last decades, major emissions of air pollutants from transport decreased. However, road transport remains one of the most significant sources of air pollution. In Slovenia in 2020 road transport contributed 38 % to the total emissions of nitrogen oxides. In the period 1990-2020 emissions of substances that cause acidification and emissions of ozone precursors in transport sector declined by 74 % and 77 %. In the period 2000-2020 emissions of particulate matter decreased by 56 %.

Greenhouse gas (GHG) emissions from transport in Slovenia almost tripled between 1986 and 2019. In the EU, GHG emissions from transport also exceed economic growth on average, but significantly less than in Slovenia; in the period 1990-2019, they increased by 23.6% in the EU-28. The main source of GHG is mostly road transport, which contributes as much as 99% of all GHG emissions from transport.

Although the annual number of road traffic fatalities in Slovenia has been declining for decades and has decreased to about a third since independence, traffic still requires an excessive tax. The number of traffic accidents with victims or serious injuries is at the level of 30 years ago, the number of serious injuries is already 15 years stagnant. Traffic accidents have claimed an average of almost 110 lives per year over the last ten years, and fortunately, the number of deaths in traffic accidents has been slightly decreasing over the past ten years.