Integrating Biodiversity in Transportation

Building new transportation routes and corridors involves cutting through our natural environment. This can include highly sensitive areas such as bogs and wetlands, lands used for growing food, forests that capture carbon dioxide from the air, or grasslands that are grazing grounds for a variety of animal species.

Every time a new road or train track is built, it has the potential to have a detrimental impact on our natural environment.

How do we minimize this impact? What actions can we take to protect and restore the natural environment?

It starts with ensuring that biodiversity is considered at every phase of the project.

Project Design and Route Choice

The ecological effects created by linear infrastructure cause fragmentation of natural habitats, and have the potential to reduce populations of many wildlife species.

Historically, biodiversity has been associated with project constraints, constraints or even opposition to the implementation of projects. However, this mentality is changing, given the awareness of the biodiversity loss crisis and commitments by developers to protect biodiversity.

Demonstrating awareness and understanding of the need to protect biodiversity starts at the very beginning of the project development process. Route choice and route design are vital because, if schemes can be rerouted or adapted to completely avoid impacts on the most valuable elements of biodiversity, such as ancient woodland and wetlands, this prevents the need for mitigation and offsetting later. Considering biodiversity from the outset of a project’s development can help prevent delays and unexpected costs. This approach is aligned with the mitigation hierarchy and is being adopted more frequently as the cost of ecological mitigation measures increases.

There are also two different mindsets required by developers. If the infrastructure is new, and travelling through undisturbed habitat, the focus should be on minimizing the footprint and the impact, since no matter what is created, this will be worse than the undamaged pre-construction environment. Alternatively, if the scheme is in urban areas, then they should almost be seen as an opportunity for the creation of biodiversity in a degraded area. Light rail and other non-road projects can present the greatest opportunity here, and it’s always worth trying to link up with the wider environment.

Regardless of which landscape the project is facing, early consideration for biodiversity impact reduction must be taken.

Environmental Assessment

The focus of the environmental assessment (EA) process, in relation to biodiversity, has previously been on the development of mitigation to negate negative impacts. However, now there is a change in mindshift to focus on creation of an overall benefit for biodiversity throughout the project development.

An example of this is the Biodiversity Net Gain (BNG) out of the UK. It is a piece of national legislation that requires developers to generate a 10% gain in biodiversity, measured through the quantity and quality of habitat in the development boundary. This adds greater importance on avoiding impacts if developers know that they then have to pay for offsets.

The methods used to monitor and measure biodiversity are also improving alongside the increased requirements for developers. It’s also worth considering the use of digital tools during the environmental assessment process based on the benefits they can provide. This includes the use of remote sensing of habitat data, automated trail cameras to record wildlife, or other digital sensors. These, and other new tools, can assist in creating a more comprehensive EA, one that provides extensive data on things like wildlife movements and migration patterns, which can support stronger decision making during the project development process.

Stakeholder Consultation

Engaging the community on biodiversity is an important aspect of transportation project development.

There is a need to engage communities on biodiversity focused elements as well as built environment aspects, especially Indigenous communities who have extensive historical knowledge of the lands. An example of this would be the planting of a woodland as part of the project. Working with the community, the project team can appreciate whether the woodland planting is in line with the historical woodland in the region, and whether it is even appropriate for the area.

Often, nature-based solutions require community support through their lifetime and, therefore, need community buy-in before operation. There are many examples of green bridges and wetlands that have been implemented at great cost but without the support of the community.

An example of what can be done to get and keep the community engaged in the project is the use of a Digital Environment Statement. These statements provide a comprehensive digital footprint of the plans for biodiversity preservation and restoration using visual components such as maps and preliminary designs.

Project Engineering and Construction

Heightened awareness of the importance of biodiversity is now driving a shift from grey infrastructure elements to green infrastructure elements integrated into new transportation projects. A few of the more popular examples being adopted are bioswales, channels that help funnel stormwater away from the infrastructure while also removing pollution and debris from the routes, and permeable pavements, which effectively remove water from the roads at a quicker rate than traditional pavements while also replenishing nearby groundwater resources.

Then there are bigger, bolder solutions, ones that can be legitimized financially depending on the sensitivity of the surrounding biodiversity. This includes ideas like green bridges, wildlife underpasses and fish passages, and exclusion fences to repair ecological connectivity at a landscape scale. Canada has seen a recent increase in these types of solutions, especially in B.C. and Alberta along stretches of the Trans-Canada Highway.

Each of these can provide the needed biodiversity protection, depending on the area in which the new transportation route is being created.

Operations and Maintenance

In the UK, the Highways department is supporting biodiversity integration by starting to view what it calls the ‘soft estate’ of transportation routes, or the verges, hedgerows and planted areas, as a major opportunity for biodiversity.

By of their estate they have been able to generate gains in biodiversity across the whole road network. This was achieved using remote sensing in combination with ground truthing on site surveys.

There has also been a change in how maintenance is viewed with greater acceptance of ‘messy’ verges that provide far more benefit to biodiversity. This often comes with fewer costs as many of these actions simply require reducing the number of grass cuts to twice a year or removing topsoil. By changing the habitats along the length of the roads we can create biodiversity corridors rather than current landscape barriers.

It’s important to understand, from the earliest stages to project maintenance, that there is no one-size-fits-all solution to biodiversity for transportation projects. Each is unique with its own challenges related to the natural environment with which it interacts. It’s important to start at the beginning, understand how the project impacts nature, work with the community to implement the best possible solutions for biodiversity protection and restoration, and continue to improve during operations and maintenance of the asset.