Overview

Integrating biodiversity conservation considerations in all phases of the infrastructure development life cycle is key to achieving more sustainable transport systems. The project life cycle phases are strategic planning, design, construction, operation and maintenance, upgrading or adaptation, and finally decommissioning (where applicable).

To ensure that nature and the benefits it provides to people are mainstreamed into the transport infrastructure life cycle, countries and regions should align their transport policies and strategies with international environmental agreements, and all relevant sustainability standards and regulations. Potential benefits to ecosystems and the services they provide to people could also be preserved or restored if infrastructure is adequately planned, and during operation, particularly when upgrades or adaptations are undertaken.

Main messages

The transport sector is one of the most important drivers of biodiversity loss as it causes habitat degradation, landscape fragmentation, pollution and wildlife mortality.
The effects on biodiversity are non-linear, long-lasting, and mostly deleterious. They vary considerably among species, habitats, and regions, and require context-specific solutions, systematic monitoring as well as large scale strategies to avoid crossing tipping-points.
The use and maintenance of transport infrastructure affects surrounding ecosystems through a variety of toxins, noise, light, changes in microclimate, and biotic pollutants. The combined disturbance, or ‘effect zone’, by far exceeds the physical footprint of infrastructure.
New habitats that benefit some species in transformed landscapes can be created through transport infrastructure. However, these habitats can also facilitate the spread of invasive alien species by providing migration corridors or suitable habitats and may also create ecological traps attracting animals to areas with unsuitable conditions or a high mortality risk.
The transport sector has a responsibility to mitigate its direct effects on nature, such as habitat loss and transformation, pollution, and corridor, barrier, and mortality effects. The negative effects interact and lead to habitat fragmentation and other cumulative effects such as land exploitation and urban development. To address these secondary effects, the transport sector must take an integrated and holistic approach and collaborate with other stakeholders.
Even with the best mitigation efforts, there is likely always a residual net loss of nature when new transport infrastructure is built. Improving existing infrastructures may offer opportunities to reduce the impact and achieve a net gain for nature.

Actions to take

Infrastructure planning is a multilateral process and should include meaningful consultation with local communities and other relevant stakeholders, especially during strategic planning and design where cumulative impacts come into play and are often poorly assessed. The consideration of specific issues related to biodiversity implies broadening the approaches to cumulative effects at the territorial level.
When assessing and addressing the impacts of transport on nature, the mitigation hierarchy should be used: ‘avoidance-reduction-compensation’ (see Chapter 3 – The mitigation hierarchy). This applies to direct, indirect, and cumulative effects.
Impact assessment should follow and comply with the European Union directives for Strategic Environmental Assessment (SEA Directive 2001/42/EC) and Environmental Impact Assessment (EIA Directive 2014/52/EC).
Whether any Natura 2000 sites are potentially affected by the analysed infrastructure project, an Appropriate Assessment must follow the Habitat Directive’s requirements (1992/42/EEC).
Adaptive infrastructure maintenance plans are recommended as they allow to identify opportunities to benefit biodiversity, adapt to climate change and increase infrastructure resilience.
Defragmentation of existing infrastructure must be considered in all upgrading projects as well as in maintenance practice. Providing safe wildlife passages contributes to reduce animal-vehicle collision risks, allow the movements of animals and restore ecological connectivity.

Gaps of knowledge and future research

Climate change impacts are not well integrated into current transport planning. This includes impacts on species as they move across the landscape to adapt to climate change and impacts on infrastructure due to climate change-induced events (e.g. floods or erosion).
The adoption of new technologies should be considered to allow better integration of data into plans and help make decisions more efficiently.