The Fact Sheet on Sensitive Areas shows that particularly sensitive areas, such as mountainous regions, wetlands or coastal zones, are extremely vulnerable to the impacts of transport. The rapid increase of road transport in Europe has contributed seriously to the deterioration of air quality and caused widespread noise nuisance.  Also the ever-increasing spread of transport infrastructure is a major threat to biodiversity.

The Vienna Declaration of the UNECE Conference on Transport and the Environment (1997) defines sensitive areas as “areas where the ecosystems are particularly sensitive, where the geographic conditions and the topography may intensify pollution and noise and where unique natural resources or unique cultural heritage exist”. The Declaration asks that sensitive areas be protected from the negative impact of transport on human health and the environment. It also recognizes the need to develop and implement additional and stricter measures for freight transport in sensitive areas.

Ecologically particularly sensitive areas constitute the weakest links in the chain of ecosystems and landscapes, which makes them a highly challenging issue for transport policy and system development, above all with a view to the planning of transport infrastructure.

International Agreements and national framework programmes call for individually tailored solutions for sensitive areas. At the European level, the Vienna Declaration on Transport and the Environment and the Declaration of the CENTRAL European Initiative  “Towards Sustainable Transport in the CEI Region” were the first initiatives to focus on sensitive areas as a field of action for sustainable and environmentally compatible transport. The Alpine Convention sets forth clearly defined objectives for transport in the sensitive Alpine Region.

In 2001, the Assembly of the International Maritime Organization (IMO) adopted new Guidelines for the Identification and Designation of Particularly Sensitive Sea Areas (resolution A.927(22)). A Particularly Sensitive Sea Area (PSSA) is an area that needs special protection through action by IMO because of its significance for recognized ecological or socio-economic or scientific reasons and which may be vulnerable to damage by international maritime activities. There are currently seven designated PSSAs, three of which are in the UNECE region: the sea around the Florida Keys, (United States, 2002), the Wadden Sea (Denmark, Germany, Netherlands, 2002); and Western European Waters (2004).

The guiding principles for sensitive transport solutions in sensitive areas can be derived from the three basic pillars of sustainable development: (1) ecologically compatible by complying with environmental quality and health targets; (2) economically profitable by providing for efficient transport systems and good accessibility; (3) socially just due to safe traffic and transport systems and balanced mobility opportunities.

The following principal requirements can be defined for traffic and transport systems in general and for infrastructure requirements of ecologically sensitive areas in particular: (1) developing a perspective for a sustainable and environmentally compatible transport development taking into account the requirements of sensitive areas; (2) determining transport development options and a suitable mix of measures for transport development in sensitive areas; (3) particular requirements of infrastructure in sensitive areas.

Other actions that can be undertaken to further assess transport-related environmental impacts on ecologically particularly sensitive areas with the aim of maintaining or bringing the impacts of transport on human health and the environment below acceptable levels include:

• Identification and agreement on criteria to designate ecologically particularly sensitive areas;
• Development, implementation and monitoring of specific policies and subsequent measures, based on these agreed criteria, to protect these areas. Particular attention should be given to measures to achieve a substantial modal shift towards transport modes sustainable for environment and health. Also, effective transport demand management systems should be introduced to reduce the environmental damage and health risks of road traffic, to internalize the external costs of transport and to cross-finance environmentally sustainable transport infrastructures in ecologically particularly sensitive areas;
• Further support for developing guidelines and research and pilot projects.