The idea of Trans-European Networks (TEN in the EU jargon) emerged by the end of the 1980s in conjunction with the proposed Single Market. It made little sense to talk of a big market, with freedom of movement within it for goods, persons and services, unless the various regions and national networks making up that market were properly linked by modern and efficient infrastructure.

The construction of Trans-European Networks is also an important element for economic growth and the creation of employment 

The Treaty establishing the European Union provides a sound legal basis for the TENs. Under the terms of Chapter XV of the Treaty (Articles 154, 155 and 156), the European Union must aim to promote the development of Trans -European Networks as a key element for the creation of the Internal Market and the reinforcement of Economic and Social Cohesion. This development includes the interconnection and interoperability of national networks as well as access to such networks.

According with these objectives, the Community is developing guidelines covering the objectives, priorities, identification of projects of common interest and broad lines of measures for the three sectors concerned (Transports, Energy and Telecommunications). The European Parliament and the Council approve these guidelines after consultation of the Economic and Social Committee and the Committee of the Regions.

A large number of projects of common interest have benefited from financial support of the Community budget through the TEN-budget line as well as the Structural Funds and Cohesion Fund. The European Investment Bank (EIB) has also greatly contributed to the financing of these projects through loans.