What is GBI and why is it important?

• GBI is a network of multifunctional natural and semi-natural features integrated into the built-environment that support a range of benefits.
• Green components include parks, open spaces, allotments, street trees, woodlands, green roofs and walls, bee bricks, and bird/bat boxes.
• Blue components include rivers, streams, ponds, rain gardens, permeable paving, swales, filter strips, which are all integrated into the management train of Sustainable Drainage Systems (SuDS).
• Well-placed GBI features, especially having nature on people’s doorsteps, help to give streets a sense of place rather than purely being a movement corridor.
• GBI features are key to projects providing Biodiversity Net Gain, nature recovery, climate change, and access to nature all of which have been asked of by Defra (Environment Act) and DLUCH (Levelling Up and Regeneration Bill, National Planning Policy Framework).
• A key benefit for the transport sector to realise is that GBI offers resilience to extreme heat by offering shading and cooling, as well as resilience to climate-related flooding and drought by offering drainage and water storage solutions.
     

Well-designed GBI features must be:

• Integrated – they should compliment a project and be planned for from the start, not an afterthought. The value of the GBI feature (i.e., street trees) should work with the value of it’s surroundings (i.e., pavements).
• High quality - quality underpins functionality at each stage of the development process. Every site will be different, and there is no ‘one-size fits all’ approach. However, there are key principles of what good quality looks like which must be a key priority.
• Thriving - many GBI features are living organisms that will want to grow and thrive, they should be allowed to do this and chosen specifically with this in mind.
• Multifunctional – one feature can have many benefits associated with it, which should be recognised.
     

How can we maintain GBI?

• We need our landscapes to be as low maintenance as possible. If we do the job properly and GBI is planted well and established, there should be very little maintenance cost – only the need to inspect for safety.
• A lot of money is spent on capital improvements and maintenance is let down. We all have a role to play in setting up maintenance regimes and making sure they are enforced.
• We need national guidance, and/or a code of good practice on maintenance.
        

What can we as transport professionals do?

• Consideration of GBI is not a traditional skill for many transport professionals, we must therefore work with other types of professionals such as planting specialists to consult on species and soil types etc.
• Whilst doing this we also need to up-skill to get ready to maintain these assets so that we can meet the benchmarks and policies that are put in place by government bodies such as DLUCH and Defra.
• We must make sure that we invest in GBI. We asked our webinar attendees to give examples of projects that should be included in RIS3 to restore a resilient and more biodiverse environment along the strategic road network – check out the answers below:
       

It’s not as complicated as it may seem!

The panel referenced many guidance documents to help support transport professionals when implementing GBI features in their projects which can be found here:

ciria SuDS Manual 

BwN case study resources – Oakfield, Barne Barton, Cornwall Council Design Guide

ICE Manual of Blue-Green Infrastructure

First Steps in Urban Air Quality

First Steps in Trees and New Developments

First Steps in Urban Heat

First Steps in Valuing Trees and Green Infrastructure