The new Butterfly Handbook is been jointly funded by the Highways Agency and English Nature to provide a valuable reference manual for conservationists and highways engineers around the world.
The minister for road safety, Dr Stephen Ladyman, said: 'The new Butterfly Handbook is a welcome step forward which will help road designers and conservationists to work together to protect butterfly populations. The Highways Agency takes its environmental responsibilities very seriously. This new guide now demonstrates the wide range of steps it takes to protect butterflies and other wildlife in the course of its work. It is an excellent example of partnership working between two government agencies, the Highways Agency and English Nature.'
In the foreword to the handbook, Dr Martin Warren, chief executive of the Butterfly Conservation charity, said: 'Butterflies have probably never been as endangered as they are today following decades of loss of key semi-natural habitats such as flower-rich grasslands. This report is extremely valuable and timely as it concerns an increasingly important habitat for butterflies and other insects.
'With a little planning, road verges can be made even better places to conserve butterflies and other wildlife as they can provide suitable breeding habitats for many species and provide crucial links between the patches of habitat that remain.'
The Butterfly Handbook contains examples of how habitats can be created, managed and monitored along the road network. Features include wide verges and central reservations planted with suitable scrub and hedges which create additional shelter and habitat for the butterflies.
Deep cuttings and embankments, reservoirs used for storage of storm water from the road surface and land within new road schemes can also be effectively managed to increase butterfly populations.
English Nature's chief scientist, Dr Keith Duff, said: 'Road construction has had a massive impact on the English landscape both positive and negative. This joint publication, the first between English Nature and the Highways Agency, brings together a huge body of research which examines how butterflies can benefit or be disadvantaged by road construction. We hope that road engineers across the country will use the handbook to design and construct roads which enrich the value of our countryside for butterflies and other species.'
Of the 56 species of butterflies resident in Britain, 26 are recognised under the UK Biodiversity Action Plan as species that need habitat protection to survive in healthy numbers.
The guide says: 'In some cases, particularly in intensively farmed landscapes, roadside habitats may provide the best chance of seeing butterflies in the area.'
The handbook gives case studies which show where butterfly-friendly measures have been incorporated into major road schemes. These include the M40 extension from Waterstock to Wendlebury in Oxfordshire whose route was altered to protect local Black Hairstreak butterflies, and the new A30 Bodmin to Indian Queens dual carriageway in Cornwall which replaces a heavily congested route across Goss Moor, a designated Special Area of Conservation and home to the rare Marsh Fritillary butterfly.
The new A30 road will skirt around the edge of the moor and part of the old road will be turned into a cycleway and footpath, encouraging butterflies and other wildlife.