Even though modern road network is the main prerequisite for sustainable economic development of every country, intensive road construction also has a negative influence on surrounding life and environment. With its unique characteristics, motorways presents large obstacle in landscape, intersecting the habitual migratory wildlife routes in their natural surroundings. One of the measures from adverse motorway impacts includes ensuring natural wildlife migrations across motorways. One of such measurements is construction of wildlife crossings which are well-established in the Croatian road planning process and relevant legislation. Therefore, it is created a favourable environment for the development and adoption of new technologies for their construction. Buried Flexible Corrugated Steel Structures (BFCSS) presents modern construction technology for wildlife crossings with the variety of opportunities in term of spans and shapes. Technology of BFCSS for civil engineering infrastructure projects is well known in countries with developed steel industry and expensive labour. But in this part of Europe, south-eastern Europe, it has been unfairly neglected and just sporadically used. In order to promote new technology and achieve progress in the field of road construction, modern way of wildlife
crossings construction will be presented. In this paper, basic engineering properties so as the designing details and usage possibilities of BFCSS will be presented. Special emphasis will be given on practical experience of their use in the construction of wildlife crossings as well as on the use of long-span structures.

Buried Flexible Corrugated Steel Structures; wildlife crossings; long-span structures; design details