Cockcrow Bridge

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As part of the £317 million M25 Junction 10 / A3 Wisley improvement scheme for National Highways, AtkinsRéalis played a leading role in designing and delivering Cockcrow Bridge, the UK's first heathland green bridge.

Built across the A3 in Surrey, the bridge is a flagship feature of the wider M25 J10 programme, improving journeys at one of the UK's busiest motorway junctions while restoring one of the country’s rarest habitat types, lowland heathland which supports species that cannot thrive elsewhere.

Located between Ockham Common and Wisley Common, Cockcrow Bridge sits within a highly designated landscape that includes a European designated Special Protection Area (SPA), a Site of Special Scientific Interest (SSSI) and a Local Nature Reserve (LNR). It provides a safe crossing for wildlife, pedestrians, cyclists and horse riders, creating a vital link across a previously fragmented area.

Balancing infrastructure and environmental enhancement together

The M25 Junction 10 / A3 Wisley improvement scheme was commissioned to address longstanding congestion and safety issues while improving connections for road users and local communities. Providing these outcomes within such a sensitive environment required a solution that balanced transport performance with environmental protection and restoration.

Working for and closely with National Highways, Balfour Beatty and environmental stakeholders, AtkinsRéalis led the multidisciplinary design of the scheme, which included the design of Cockcrow Bridge and a suite of habitat creation and restoration measures across the wider landscape of the junction. The team also supported environmental planning and stakeholder engagement throughout the project’s development and delivery.

Through collaboration with Balfour Beatty and the use of advanced digital tools, AtkinsRéalis helped optimise the scheme to reduce material use, lower embodied carbon and enhance constructability. Design innovations including lowering the junction level, shortening bridge spans and adopting efficient construction methods which reduced programme, cost and carbon impacts while maintaining long-term operational performance.

Creating a new model for nature-connected infrastructure

At 63 metres long and 30 metres wide, Cockcrow Bridge is a mixed-use green bridge with separated areas for wildlife and people, and it demonstrates how infrastructure can support both active travel and nature recovery. The bridge connects heathland habitats that have been separated by the A3 for decades, creating a continuous corridor for wildlife movement.

Approximately 10,000m² of heathland turf supporting existing vegetation, soils and seedbanks was translocated onto the bridge, helping establish a rare lowland heathland habitat at pace.

Cockcrow forms part of a wider programme of habitat enhancement that the project has delivered which includes heathland restoration, woodland creation and enhancement, enhancement of waterbodies and grassland and creation of new ditches and ponds designed to strengthen nature recovery and climate resilience across the local environment.

It represents an additional investment in nature recovery, demonstrating how major infrastructure can go beyond statutory requirements to reconnect habitats and support ecological resilience at landscape scale.

Cockcrow Bridge clearly shows how infrastructure can deliver lasting benefits for both people and nature. By reconnecting Wisley and Ockham Commons, we're supporting wildlife, local communities and the recovery of one of the UK's most threatened habitats.

Jonathan Wade

Senior Project Manager, National Highways

Establishing lasting impact for people, place and nature

Cockcrow Bridge shows how major infrastructure projects can deliver social and environmental value together. A range of species have already been recorded using Cockcrow, including deer, foxes, reptiles and bats.

Across the wider M25 J10 scheme, the project will increase network capacity and support economic growth while creating a more sustainable and resilient natural environment. Cockcrow is also helping establish valuable learning for future green bridge projects across the UK through long-term monitoring and knowledge sharing.

Cockcrow’s innovative design and approach have been recognised through industry awards, including the National Highways Good Road Design Award and the Landscape Institute’s Design Awards.

Creating sustainable, resilient networks is at the heart of what we do. Cockcrow Bridge leaves a legacy that supports connectivity and long-term environmental recovery.

Victoria Gilbey

Associate Director (Ecology), AtkinsRéalis

Key facts

£ 317 m

M25 J10 improvement scheme

UK's 1 st

heathland green bridge

63m x 30m

wide mixed-use wildlife crossing

Circa 10,000 m²

of healthland turf translocated onto the bridge

Markets

Transportation
Services

Engineering & design
Location

UK
Client

National Highways
Collaborators

Balfour Beatty

UK's first heathland green bridge

Balancing infrastructure and environmental enhancement together

Creating a new model for nature-connected infrastructure

Cockcrow Bridge clearly shows how infrastructure can deliver lasting benefits for both people and nature. By reconnecting Wisley and Ockham Commons, we're supporting wildlife, local communities and the recovery of one of the UK's most threatened habitats.

Establishing lasting impact for people, place and nature

Creating sustainable, resilient networks is at the heart of what we do. Cockcrow Bridge leaves a legacy that supports connectivity and long-term environmental recovery.

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