How can transport infrastructure make a positive contribution to the local environment?

The Occasion

Transport infrastructure is often seen as detrimental to the local environment, generating pollution, carbon emissions, and negatively impacting local ecology. More recently, however, it has become clear that much of the UK’s transport infrastructure, including our road and rail networks, are providing important wildlife and floral habitats and have a major role to play in supporting local biodiversity. As we recover from the pandemic and plan transport infrastructure for a more sustainable future, the time is ripe to consider how this infrastructure can make a more positive contribution to the local environment.

To discuss this crucial topic, the ITC was delighted to welcome a distinguished panel of experts at our digital Spring Discussion Event held on 7th April 2022. The discussion was chaired by ITC Commissioner and transport expert Kristine Beuret OBE, and the expert panel included: Jo Lewington, Chief Environment and Sustainability Officer at Network Rail; Stephen Elderkin, Director of Environmental Sustainability at National Highways; and Jon Riley, Divisional Director for Biodiversity at Temple Group.


How can transport infrastructure contribute positively to the environment? Key issues from the speakers:

  • Jo Lewington explained how the rail network was supporting local ecology. She highlighted Network Rail’s environmental sustainability priorities, including developing a low emissions railway, minimising waste, creating resilience to climate change and improving biodiversity on the rail estate. Network Rail managed 52,000 acres of land, she noted, and had undertaken a major mapping exercise to understand the distribution of habitats and opportunities for ecological renewal across the network. A new target had been set to achieve a net gain of natural habitat across the rail estate and they were working with adjacent landowners to achieve this. She reported that much of the Network Rail estate was bramble scrub and broadleaved woodland, although areas had been identified for habitat improvement and work was ongoing to identify the most ecologically valuable areas and transform scrub into species-rich grassland. Collaborative work with National Highways was also underway, she reported, since major road and rail lines often followed the same corridors. She concluded by observing that successful techniques for habitat improvement often required pilot trials, and in some cases these had led to initiatives such as the transformation of ballast into grassland.
  • Steve Elderkin reported on how National Highways was helping the local environment. He explained that National Highways had set new environmental objectives including delivering sustainability improvement projects, obtaining better data on the organisation’s ecological assets, and integrating environmental sustainability into the planning and funding processes for roads. Nature-based solutions were an effective tool for managing flood risk on the strategic road network, he noted, and efforts were now underway to scale up the success of initial pilot projects. New mapping techniques had been developed for the National Highways estate, which were enabling a much better understanding of biodiversity across the strategic road network. Roadside verges were often important low nutrient grassland habitats, he reported, supporting many rare species of native UK flora, and major new initiatives were underway to improve the scale of this habitat by removing over-fertilised topsoil and changing mowing regimes. These improvements were helping the organisation to counter biodiversity loss, ensure that construction work minimised its impact on local ecology, and develop new enhancement projects to improve roadside habitats. Projects had been identified that would create more diverse habitats and additional planting across the estate was helping to achieve this.
  • Jon Riley provided a wider perspective on biodiversity and transport infrastructure. He explained that the Lawton Review of 2010 had identified the importance of improving England’s ecological network and transport infrastructure had a major role to play in this. Commitments made in the new Environment Act laid out a 25-year plan for improving nature recovery, and set legally binding targets to halt the decline in species abundance across Britain by 2030. To achieve these objectives and result in a nature positive outcome, organisations could increase the biodiversity value of their habitats or acquire biodiversity units or credits from approved providers. Opportunities existed for transport infrastructure providers to improve their ecological footprints by connecting and buffering valuable habitats, reflect local ecological characteristics, and deliver habitat creation in partnership with other organisations. The HS2 Green Corridor was a good example of these possibilities in action. However, challenges remained, including the difficulty of assessing biodiversity improvements due to lack of data, and future uncertainty about the impact of climate change on habitat creation and management.

  • Key themes raised in the Q&A discussion:

    The discussion was chaired by transport expert and ITC Commissioner Kris Beuret OBE

    1. Better data is essential for good biodiversity management on networks. A number of attendees asked about good data collection and noted the importance of this for evaluating habitat improvement schemes. It was pointed out that the CORINE land use data was not especially accurate but it was hoped that higher-resolution satellite monitoring would overcome this. Such satellite data could be shared between infrastructure organisations to help them achieve common goals. The measurement of biodiversity was also challenging and improved assessment methods and data collection would be needed to improve this. Others proposed that it would be helpful to include mapping of community engagement levels in any assessment of environmental schemes.
    2. How should we assess the value of ecological improvements? It was observed that it was often quite challenging to place a monetary value on ecological improvement schemes and this could cause problems in assessing the value of such initiatives. Improved evaluation techniques that took account of the multitude of wider benefits arising from improved biodiversity and habitat development would be important. Others suggested that there would inevitably be negative ecological impacts resulting from new infrastructure construction, but perhaps this could be offset by environmental improvements achieved along existing parts of the transport network. There was also some support for the idea that failing to make adequate provision for biodiversity improvements should count against a proposal.
    3. Developing a broader range of ecological initiatives would be welcome but will take time. Several guests suggested that it would be good to see a broader range of ecological initiatives across the transport networks and welcomed the work that Network Rail and National Highways were doing. Others asked the expert panel what they saw as the biggest challenge to improving biodiversity. A key response was the issue of time, given that many initiatives could take years or even decades to bear fruit in terms of habitat improvement and species diversity, which meant that patience was required from stakeholders. A question was also asked about initiatives to reduce the problem of public littering which was particularly a blight along the strategic road network and impaired habitats.
    4. How do safety considerations match up with ecological objectives? Some questions related to the potential conflicts between safety considerations and the aim of improving ecological diversity and wildlife habitats. This was evident on the rail network in the pressure to cut back trees in order to reduce the risk of leaf fall or branches collapsing during storms. For the road network issues of visibility could be an issue where vegetation was not cut back rigorously. And some observed that airports had problems with birds which posed safety risks to aircraft engines. The panel agreed that safety had to be paramount but it was also important to remember that habitats were not limited to trees and woodland, and other habitat types including grasslands were important for biodiversity.
    5. Collaboration with the local community and other organisations can help to leverage the success of environmental projects. The importance of collaboration between infrastructure managers and the local community was highlighted by several guests. It was observed that this was already happening in some areas, such as Network Rail’s engagement with the Community Rail Network, but more opportunities existed to involve local groups which were often keenly interested in habitat improvements across their neighbourhoods. Such an approach also revealed the value of focusing on ‘smaller scale’ infrastructure such as roundabouts and station spaces, in addition to the major habitat areas adjacent to road and rail corridors. Delegates also welcomed the increased collaboration between Network Rail and National Highways to achieve biodiversity objectives and looked forward to this expanding.