Transportation is one of the major sources of greenhouse gas emissions, accounting for 24 percent of carbon-dioxide emissions globally, and 21.7 percent in the EU (IEA (2017) and Eurostat GHG data) and represent about one-third of the final energy consumption. It is a more than 90%  fossil-fuel dependent sector (especially oil). Other transport-related pollutants, released in higher concentrations in densely populated areas, cause health problems and environmental damage locally and at greater distances, e.g. in the form of acid rain or acid deposition. Other negative impacts of transport include traffic jams, noise pollution and heat traps in urban areas, caused by local heat formation due to extensive parking zones that occupy a substantial share of public space in cities, displacing green areas.

Transport is the only upward trending sector in emissions over the last two decades. While the EU28 lowered total GHG emission by 18.6% between 2000 and 2018 transport emissions grew by 2.4%, becoming the second largest at 24%.

The Danube Region is especially affected by the environmental effects of the transportation since a major transit route passes over the countries of the region from Turkey and Greece in the direction of Germany and Western Europe. Currently, diesel-fuelled road transportation is absolutely dominant in this route, being the principal responsible for the environmental damages. Growth of GHG emission in the Danube Region has been faster than the EU average, except for Germany, which is the only DR country to register a reduction. In the period DR sectoral emissions grew by only 6.8% but removing Germany it jumps to 52%.


Germany is considered to have one of the highest penetration of motorways (the German motorway network is almost 13 thousand kms long) but Slovenian values are even higher. Romania, Poland, Bulgaria and Slovakia have quite small motorway networks in absolute values and in terms of penetration, however they are connected to the neighbouring countries by growing networks of E-roads. The network of E-roads is quite stable in the region since 2010, only Slovakia got significantly more connected to its neighbours. Motorway networks expanded dramatically in Romania, Poland, Bulgaria and the Czech Republic, but almost every country presented some growth.

Change of road network density (REKK, 2018)

Railway density decreased or stagnated in every country in the region excepting Hungary since 2010, so it was quite common in most of the countries that some network infrastructure had to be withdrawn from operation. In case of waterways the density was stagnating, Croatia was the only country where there was a significant expansion of waterway network.

Compared to 2010, road transportation further increased its share in all DR countries, except for Hungary, where it remained unchanged. Share of rail transportation decreased in most of the countries, only Slovenia, Romania and Hungary could achieve some development in this regard, while share of inland waterways decreased in every country.

Modal split of freight transport, tkm, 2010-2016 (REKK, 2018)


Transport-related GHG emissions have increased in most of the DR countries since 1990. Their level more than doubled in Poland, the Czech Republic and Slovenia, and increased substantially (more than 50%) in Montenegro, Austria and Croatia. Only Germany and Slovakia managed to keep the change at the minimum, while emissions dropped in Moldova and Ukraine in the first years of the period, because their transportation sectors went through a dramatic structural change after the collapse of the Soviet Union.

Change in GHG emission in the transport sector, compared to 1990 (REKK 2018)


The transport sector does not have an EU-wide decarbonisation target, instead leaving individual member states to pursue a target related to the share of renewable energy within the total energy consumption of the sector (RES-T).

The EU’s Sustainable and Smart Mobility Strategy lays the foundation for how the EU transport system can achieve its green and digital transformation and become more resilient to future crises. It identifies a total of 82 initiatives in 10 key areas for action (“flagships”), each with concrete measures by 2030 and 2050. The main policies introduced in the EU aiming at reducing carbon and air pollution emissions from transportation include the Renewable Energy Directive II setting a targeted 14  % share of renewable energy use within the final energy consumption of transportation by 2030, the Fuel Quality Directive (1998/70) including common standards for petrol and diesel fuels used in vehicles as well as requirements related to biofuels, the Regulations related to GHG emission performance standards for new passenger cars and vans (2019/631). The continuously improving EURO emission standards (at present EURO VI) define acceptable limits of exhaust emissions of NOx , hydrocarbons, CO and PM for new vehicles sold in the EU, regulated by several EU directives amending 70/220/EEC. The alternative fuels infrastructure directive (2014/94/EU) prescribes the installation of an appropriate number of refuelling stations by 2025 along roads and at ports, enabling the TEN-T Core Network to serve HDVs with LNG. Hydrogen fuelling stations also have to be installed by the same date, although experts doubt that the deployment of hydrogen vehicles will improve at the same pace. The Connecting Europe Facility (CEF) Regulation (1153/2021) provides the financial background for improving the European transport sector infrastructure


Policies aiming to reduce GHG emissions in the transport sector can be categorised based on the following:

  • Fuel Switch: To promote the switch from fossil fuels (mainly gasoline and diesel) to electricity, biofuels or other alternative fuels (e.g. hydrogen) with less environmental impact. Fostering the penetration of electric vehicles, increasing the share of biofuels, and electrification of railways also belong to this category.
  • Modal Shift: To make more efficient and less emitting transport modes like public transportation, cycling and walking (non-motorized), and railway for freight transportation more competitive and attractive for users.
  • Efficiency Improvement: Fuel switch and modal shift both lead to higher energy efficiency, however, it is also crucial to enhance the efficiency of the conventional transport modes and technologies.

These policy goals can be achieved with a variety of measures and combinations falling within four broad categories: (1) infrastructure investments, (2) financial incentives (subsidies, taxes and fees), (3) regulatory obligations and (4) campaigning / awareness raising and removal of non-physical bottlenecks (such as regulatory barriers).

However there is a complex interaction between measures and targets. For example, emission-based taxation of passenger cars can accelerate the penetration of electric cars (Fuel Switch) but can also divert people to public transportation or non-motorised transport modes (Modal Shift), while incentivizing drivers to choose cars that consume and pollute less (Efficiency Improvement). By making environmentally friendly alternatives more price competitive, passengers and companies will make these choices economically. Additionally, direct obligations for renewable sources like biofuel mandates or green public procurements should also be an important part of the policy landscape.


Infrastructure investments

Five categories for infrastructure investments were developed according to affected modes:  development of (i) electric vehicle (EV) chargers; the (ii) development and (iii) electrification of railway systems; (iv) bicycle and (v) pedestrian infrastructure.

The emergence of electric cars (and thus the reduction of transport emissions) depends largely on the development and perception of the charging network. Most DR EU countries are in advanced stages of implementing and planning charging infrastructure. The most ambitious by 2030, Austria plans to achieve 100% network coverage at motorway rest stops and Germany aspires to reach 1 million charging points.

The development and the electrification of railways is also an area of focus where most countries are already taking active steps. Some of the countries primarily focus on the development of railway passenger transport (SK, RO), while others (AT, HU, CZ, DE, HR, SI ) also take measures to increase the share of rail relative to road freight transport.

Most countries also see the potential for reducing emissions in the development of cycling infrastructure, which can replace several forms of motorized transport. Some like Czechia and Germany have complex national cycling development strategies, but only Slovenia and Austria have a strong focus on the development of footpath infrastructure.

Financial incentives

Most DR EU countries have implemented active subsidy (purchase premium or bonus) programme for the purchase of EVs (and in some cases for plug-in hybrids) with some including its gradual phase out in the long run. This usually targets individual private purchases, but some measures also cover business sector fleets.

Purchase subsidies for public transport vehicles aim to increase the number of more eco-friendly alternatives in each country. In some cases this equates to the purchase of electric buses (AT, HU, RO), in others replacing bus lines to eco-friendly alternatives like trolleys, trams, subways, and for some CNG (compressed natural gas) or hydrogen-based buses. While Austria procures electric buses to close out its diesel fleet, Hungary intends to procure Euro 6 diesels in the early years.

Like the above financial incentives, different types of tax allowances of EVs have become common in the DR countries, including exemption (or reduction) from the registration fee and motor vehicle tax (AT, HU, DE, CZ, RO) and in some hydrogen and EVs for companies (DE, HU, AT). In addition to these tax allowances, countries and local governments are trying other forms, such as exemption from parking fees and tolls and entry to low-emission zones. Austria, Germany and Slovenia have envisaged and already apply taxes based on vehicle CO2 emissions, which is a more sophisticated and suitable way of incentive taxation.

The support of rail transportation as an alternative to highly polluting transport modes is carried out by reducing taxes on train tickets and increasing airfare taxes, new toll policies (DE, SK) and increasing the share of rail freight (AT, HR).

Regulatory obligations

The green public procurement obligations introduced or to be introduced are similar across all countries: either a ratio is set for newly acquired vehicles or a target for the whole fleet is set for different years. In most countries, the regulation applies to public service vehicles, but in Czechia it also extends to the purchase of public transport vehicles. Several countries (DE, SI , SK, CZ) have already executed public procurement specifically to lower the emissions of the vehicle fleet.

For first-generation biofuels, several countries are setting escalating blending mandates, though Germany is locking its share of first-generation biofuels in 2020 (5.3%) to 2030 under RED II. All countries seek to promote advanced biofuels, but most are in the very preliminary stages of action and do not explicitly mention the related regulation of RED II.

In order to reduce sectoral emissions, several countries plan for and apply regulations restricting the purchase and use of conventional vehicles (BG, RO, AT).

Low-emission zones are geographically defined areas that limit access of vehicles on the basis of their emissions in order to improve air quality. Some countries (HR, BG) are only planning to establish and regulate these zones while others have already implemented measures (CZ, SK).

Information and awareness campaigns

Another way to reduce emissions is through various information campaigns that raise public awareness for a specific mode of transport or the concept of sustainable transport in general. In addition to campaigns, trainings that help to teach eco-friendly driving skills can also be included.


Today biofuels accounts for the overwhelming majority of renewable energy sources in transport sector.

Figure 1 presents the 2030 targets (with additional measures or WAM) outlined in NECPs, the actual 2018 share, and the projected 2030 share (with existing measures or WEM, where available). Only three countries (DE, SI , HU) committed to a significantly higher RES-T share than the obligatory minimum. Bulgaria and Romania published a 14.2% target, while Austria, Czechia and Slovakia committed to the minimum. Croatia is the only country that set a lower target.

2030 Renewable targets in the EUSDR countries

 Promoting the use of alternative fuels basically mean the facilitation of the use of renewable and low emissions fuels such as electricity and LNG. Regarding road transportation, electricity is presently an option only in short-distance, light weight transportation mainly in urban areas. It is used however to a great extent for rail transportation, therefore by diverting the shipments from road to rail, there is an opportunity to rely more on renewable electricity.

Electricity use in heavy road transportation is not yet a viable option. Before the current gas crisis natural gas technology was considered to serve as a bridging technology to low-carbon transportation (compressed natural gas – CNG, or liquid natural gas – LNG). Nowadays the role of hydrogen in green transportation in getting more and more attention.


Sustainable and Smart Mobility Strategy

Renewable Energy Directive II

Fuel Quality Directive

Regulations related to GHG emission performance standards

Alternative fuels infrastructure directive

Connecting Europe Facility (CEF) Regulation

Summary of transport relevant legislation:


EU transport in figures –

REKK (2021): Renewable targets and policies in the transport sector of the Danube Region –

REKK (2018): Promoting sustainable energy use in the transport sector of the Danube region –


DG Mobility and Transport –

EUSDR PA1A: To improve mobility and multimodality: inland waterways of the EU Strategy for the Danube Region –

EUSDR PA1B: To improve mobility and multimodality: Rail, Road and Air links –

European Conference of Transport Research Institutes –