Finding integrated solutions to road planning is one of the great challenges. It requires information on how to plan the routes of transport infrastructure to minimise impacts within the constraints of cost and engineering. Assessment of new infrastructure will increasingly focus on integrated solutions and attempt to find the route and design which produce the least impact and greatest benefit for the greatest number of interests. Such solutions may involve various combinations of avoidance, mitigation and compensation measures. The integration process is especially difficult in geographic areas where the competition for space is very high such as narrow valleys and coasts. These areas, already under pressure from housing, farming and natural drainage, are fragmented into linear strips by road and railway development with negative impacts on most interests

Integrated solutions to infrastructure planning can be viewed from several scales, namely from site, landscape and regional levels. Mitigation measures should be considered at all these scales when undertaking EIA/SEA:

• The regional level, where the potential routes are first developed in relation to topography, geology, terrain and drainage, as well as the existing infrastructure and settlement patterns.
  At this level, the total impact of the transport infrastructure network as well as individual plans is considered.
• The landscape level, where the routes of individual segments are planned to avoid serious conflict. At this level, land use, landscape, nature, culture and other interests are also taken into account.
  Landscape structure and the amount and spatial pattern of existing habitats will determine the impact of infrastructure developments.
• The site level, where specific engineering solutions are designed to meet the requirements of fitting the road to the terrain to minimise the potential impact. Physical and engineering constraints set the parameters for the design.

The following chapters provide details of methods that can be used to minimise the impact of habitat fragmentation caused by transport infrastructure.