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Transport & Environment

Study on transport-related impacts and instruments for sensitive areas

The Commission's Directorate-General for Environment has undertaken a study of transport through sensitive areas, motivated in part by the growing transport flows through areas such as the Alps. The motivation of the study is laid out in further detail in the technical annex, parts of which are reproduced further below.

The study was completed in 2004. The following definition was used at the outset:

The term ‘sensitive area concerning transport (SAT)’ denotes an area that is substantially more affected by adverse impacts from transport activity than the average, either because its environmental conditions render it extraordinarily sensitive to such impacts or because it is exposed to particularly high volumes of traffic.

The study was undertaken in two parts. Part 1 addresses the definition of a sensitive area in relation to transport on the EU level. Part 2 investigates possible instruments to use in order to address the environmental impacts of transport through such areas.

Among the main findings are the following:

  • a draft definition can be found for the specific case of sensitive mountain areas, based on the simple criteria of height and height variation;
  • the methodology could be applied to other areas;
  • initial modelling of potential policy instruments suggests that there is scope for reducing the environmental impact of transport through these areas.

The report is available for download:

Content (pdf ~0.3 MB)
Summary (pdf ~0.4 MB)
Part 1 (pdf ~5.3 MB)
Part 2 (pdf ~2.3 MB)
Annexes (pdf ~8 MB)

Workshop on the definition of sensitive areas

In parallel with the study, a workshop was organised on 18 November 2003 to look into the possibility of defining sensitive areas at the EU level. The ongoing work of the study was presented to the workshop, and its conclusions fed back into the study. If you are in a hurry, reading the summary of the study will be sufficient. The material of the workshop is available for download:

Agenda (pdf ~121Kb)
Minutes of the workshop (pdf ~281Kb)

Excerpt from the technical annex of the study:


The notion of sensitive areas is sometimes used in connection with environmental policy questions. The underlying idea is that there are some areas that require stronger protection than others. Examples are areas for nature protection (such as the Natura 2000 network) or the area covered by the Alpine convention. Sensitive areas are also referred to in certain other legislation of relevance for the environment. For example, Directive 98/70/EC on fuel quality allows for more stringent fuel quality standards linked to the health of the population in certain agglomerations and to the environment in ecologically sensitive areas. Article 5 of Directive 91/271/EEC on urban waste water treatment defines sensitive areas in the context of this Directive. In the scope of Directive 2002/49/EC relating to the assessment and management of environmental noise, there is a reference to “noise-sensitive areas”. The concept of sensitive areas is thus frequently used.

However, despite its frequent use and its intuitive appeal, there is no commonly agreed definition of what constitutes a sensitive area, which can lead to misunderstandings and a lack of clarity. In particular, there is no definition on the level of European policy. It would be in the interest of policy making to clarify the concept.

Transport and sensitive areas

Transport is among the human activities with a strong impact on the environment in general. Thus, transport through sensitive areas is likely to raise particular concerns, linked to emissions of air pollutants and noise, the transport of dangerous goods, as well as the effects of infrastructure construction on nature, human settlements and on the visual appearance.

In the White Paper on the Common Transport Policy (COM(2001) 370 final), the difficulty is highlighted of raising sufficient finance for constructing alternative infrastructures in sensitive areas such as mountain ranges. Directive 2002/30/EC on operating restrictions at Community airports introduces the concept of city airports, which due to their densely populated surroundings cause particular noise problems and therefore are granted stronger possibilities for operating restrictions. Apart from mountainous areas and densely populated areas, there may also be others. For example, Annex VI of the Marine Pollution Convention, MARPOL 73/78, of the International Maritime Organization, defines special SOx Emission Control Areas (Baltic Sea, North Sea & English Channel) because the sulphur emissions from ships operating in this area cause acidification on land. The proposed environmental noise directive defines “quiet areas in the open country”, which are to be protected as part of the objectives of noise policies.

Through traffic

The costs and benefits of transport have a spatial dimension. Generally, the benefits of transport activity are linked to the source and destination points of trips. So are the direct costs of that transport. However, the so-called external costs, including those of an environmental nature, arise along the way. Thus they are borne by actors who are spatially separated from those who reap the benefits. This is a general feature of transport economics and not specific to sensitive areas. For the internalisation of external costs, this does not generally pose a problem of principle because of a certain averaging effect: most regions both give rise to transport and suffer from the side effect of transport caused elsewhere. Thus, transport externalities can often be dealt with in a summary fashion and without looking at their spatial dimension.

However, there are certain situations where this balancing effect does not occur, such as busy transit corridors and crossings of natural barriers. In these cases, a more elaborate economic analysis should take into account the spatial separation of benefits and costs. A central issue here is the fact that a corridor of limited length is generally much smaller than the geographical areas that it connects. It is these areas where the demand for transport activity, and the economic benefits linked to it, occur. Hence, these economic benefits are likely to outweigh the environmental costs that arise inside the corridor, even in the case of large-scale local damage there. Thus, simply comparing total costs and benefits irrespective of location may not be sufficient to address this local damage.

Some of the more important candidates for classification as sensitive areas are at the same time natural barriers for transport with a limited number of transit corridors, such as mountain passes in the Pyrenees and in the Alps. The economics of transit are important in this connection when it comes to developing policy instruments.

Criteria to define sensitive areas and particularly affected areas

Areas may be said to be sensitive if they suffer more than others under a certain impact. They may have a soil type that reacts more strongly to acidification than elsewhere, they may be particularly rich in biodiversity that is threatened from human activity, they may show particularly high population density, they may have rare and fragile landscape characteristics etc.

Areas that are not sensitive in the sense outlined above may still give rise to concern if they are subject to very high levels of impact. These ‘particularly affected areas’ can be regarded as sensitive areas in a wider sense. Urban areas are obvious candidates for being seen as particularly sensitive or particularly affected areas. However, given that urban environment policy will be dealt with in depth by a thematic strategy on the urban environment as foreseen by the 6th Environmental Action Programme, the scope of the present study does not include urban areas.

Policy instruments regarding transport through sensitive areas

There are some instruments in existence that are linked to concerns about regionally specific environmental impacts. Generally, these are either economic instruments or some kind of rationing either of the transport volume, or of its environmental impact as expressed by some parameter.

Economic instruments include environmentally differentiated port and fairway dues and the Swiss charging scheme for lorries. Limitations of access can concern certain types of vehicles or fuels, such as marine special protection areas under Annex VI of the MARPOL Convention, or selective town centre closures that exempt clean vehicle technologies. Rationing approaches that target the environmental impact of transport rather than its volume include the Austrian ecopoints scheme, in which lorries have to use “ecopoints” that are linked to the certified emission of NOx of the vehicle. On the other hand, the 108% cap in that scheme is a volume rationing instrument and not one of environmental impact. The possibility has been discussed of combining rationing approaches with a distribution via tradable permits but there are currently no such systems in operation.

Connection to transport safety

The occurrence of road tunnel accidents has highlighted the link between transport volume and safety. In certain cases lorries are now only allowed to cross one-way in batches (Frejus, Mont Blanc). This amounts to a de facto limitation of the number of lorries. Thus, even if quantitative limitations are not introduced on environmental grounds, they may be on safety grounds. In this connection, allocation questions will arise. This is an additional reason for studying this area.