Known as "green bridges", they are usually planted with a variety of local trees or shrubs and other vegetation so that animals can remain mobile despite the barriers imposed by transport infrastructure. Although common in Europe and North America, only a handful have been built in Britain.
Land Use Consultants have now undertaken the first ever worldwide study of research on green bridges, on behalf of Natural England. It found they are an effective way of linking wildlife across roads, which means they could become a key aspect of the sustainability of future transport projects.
The report, "Green Bridges – a literature review", found that not only do the bridges help to prevent important wildlife habitats from becoming fragmented by aiding species movement, they are also used by wildlife as a home in their own right.
As the Government's conservation agency, Natural England gives advice on environmental impacts to planning authorities and developers to promote sustainable development. The information contained in the review will help developers and planners factor new green bridges into their construction plans or consider the greening of existing bridges.