**1. Introduction**

Sustainable bridges is a term exemplifying the general idea of sustainable development. The concept is a result of the works of a UN commission—the World Commission on Environment and Development—conducted from December 1983 to December 1987 and concluded with the report *Our Common Future*. At present, several definitions of the basic concept and its specific component disciplines are in use. One of the general definitions emphasises preservation of

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

natural environment by achieving the developmental objectives in a responsible way: *the present generations' responsibility to regenerate, maintain and improve planetary resources for use by future generations*. Nowadays, the idea has developed into specific disciplines, such as sustainable engineering, sustainable bridges [1] and sustainable design [2].

In the development of civilisation, an extensive and well-organised transportation system, i.e., roads, railway, bridges, air transport and maritime and inland navigation, safe both for people and environment, is of primary importance. The development and constant modernisation of road and rail infrastructure is connected with significant pollution emissions into the air, soil and water. Investments are accompanied by noise and traffic disruptions. These negative side effects have an equally strong impact both on people and environment. In general, they can result in a temporary or even permanent closing or changing of wildlife corridors, animal herd fragmentation, changing of nesting sites or habitats.

Roads and bridges, despite obvious differences, constitute a technically inseparable set. The name of the first and still functioning technical school, excellent *École nationale des ponts et chaussées* founded in 1747, is quite symptomatic here. Bridges as such belong to the elite area of civil engineering. This position stems from their civilisational, social, architectural as well as military role.

After the horrible experience of the first World War, the Briand-Kellogg treaty [3], renouncing war as an instrument of national policy, was concluded. History, including the most recent one, shows that military operations are still conducted on a different scale and so it happens that some are aimed at bridges. **Figure 1** shows the Hanoi bridge that was destroyed during the Vietnam War. Its crippled form is a dramatic monument to this war.

**Figure 1.** Hanoi Cầu Long Biên Bridge (1903) over the Red River—a war monument.

Sustainable bridge construction refers to the minimisation of harmful emissions during bridge construction. It is equally important, however, to design durable bridges, i.e., with minimum serviceability of 100 years as stipulated in the design standards [4]. The bridge longevity results from the structure maintenance therefore its design should take into consideration the ease of its future maintenance.

A design taking into account the future changes of traffic, both in terms of its volume and type, seems to be a great challenge. The existing methods of forecasting traffic changes cover periods from 5 to 10 years. Nobody can foresee what can happen in 50 years, [5]. Bridges have been built for thousands years and that is why it is easy to indicate the ones which have proved reliable according to various criteria. For this reason, they can be seen as sustainable bridges. The history of bridge construction referred to this paper is presented from such a perspective. In many cases, only the name of a bridge is mentioned, which results from its recognisability as well as an easy access to basic encyclopaedic information on the Internet.
