Wildlife & Traffic

A European Handbook for Identifying Conflicts and Designing Solutions

5 Planning Tools
Original version (2003)
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5.7 Costs and benefits

Planning new infrastructure or improving existing infrastructure includes economic considerations of the cost, effects and benefits of the investments. Although environmental effects are often difficult to calculate in simple monetary values, the principles of Cost-Benefit Analysis or Willingness-to-Pay methods are often used for this purpose. These methods are based on monetary calculations and should be complemented by a description of the nonmonetary benefits to give a full analysis of investments and consequences.

Calculations and descriptions of cost and benefit vary a great deal from region to region and should therefore be based on local factors.

Economic considerations are further described in the COST 341 European Review Section 8.2 (Trocmé et al., 2002).

5.7.1 Describing the costs

During the planning process multiple planning parameters are dealt with at the same time and the proposed solution is often a result of several functional, economic and environmental factors. It can be very difficult to isolate the costs that are related to fragmentation issues. An integrated approach and an iterative planning process will help develop effective solutions with low costs and high benefits. Frequently the choice of solutions determined by the topography can significantly reduce the costs of mitigation measures. In other situations the use of waste material to construct overpasses can be a low cost solution.

A description of costs related to fragmentation should include:

  • Costs derived from avoiding fragmentation by choosing longer or more expensive routes and alignments.
  • Costs derived from mitigation measures and fences added to the project for defragmentation purposes.
  • Costs derived from the limitation to optimise on other functional aspects of the infrastructure.
  • Costs derived from compensation measures caused by the fragmentation of the road or rail scheme.

5.7.2 Describing the benefits

A description of benefits related to fragmentation issues should include:

  • Benefits derived from the long-term conservation of nature and biodiversity in general.
  • Benefits from maintaining ecological coherence in the landscape.
  • Benefits derived from preserving habitats for vulnerable species. •
  • Benefits from avoiding traffic accidents caused by wildlife.

The value of nature and biodiversity conservation can be described on the basis of a Willingness-to-Pay method. Interpretation of results from these methods should take into account that avoiding, mitigating or compensating for habitat fragmentation is a long-term benefit which is often irreversible. In other words, benefits will persist as long as the relationship between infrastructure and the ecological structure is under pressure. Often benefits could increase over time when new infrastructure has secondary effects on urbanisation or other landuse change which increase pressure on habitat fragmentation. The calculation of benefits should therefore take into account the long-term efficacy of avoidance and mitigation measures.

5.7.3 Small investments in existing infrastructure

Existing older structures on roads and railways can often function as mitigation measures with only small changes or adaptations. These investments are not always critical to habitat fragmentation but can strengthen the ecological coherence of the surrouding landscape. In this situation, even small costs can have significant benefits. The recommended planning method is described in Section 5.5.

5.7.4 Longevity of solution

Longevity of avoidance, mitigation and compensation measures is crucial. Solid, persistent solutions and engineering constructions with a long life span are highly recommended. Wildlife can be very sensitive to temporary disturbance from the renovation of mitigation measures, which could increase the fragmentation effect. Cheap solutions may lead to more expensive maintenance and threaten long-term benefits. From a costbenefit point of view, mitigation measures should be designed and constructed to last as long as the infrastructure itself.