Unlocking growth through infrastructure
THE ASPIRATION
Making space for future movement
To unlock vital housing development in South Alton, Homes England and Harvington Properties needed to upgrade the local highway network. A major constraint was the narrow, Victorian-era railway bridge over the A339, a key haulage route linking the A31 to the M3. The congested Butts Bridge junction lacked capacity for future traffic, requiring a full redesign to improve safety, increase capacity and maintain live rail and road access throughout construction.
OUR RESPONSE
Engineering bold and buildable solutions
We delivered a full suite of multidisciplinary services, including Project Management – with procurement and construction supervision – Transport Planning and Civil Engineering. We led the project from early planning through to delivery, managing complex technical and stakeholder requirements throughout.
The works included the demolition of the original Victorian brick-arch railway bridge and its replacement with a 32-metre weathering steel skew span structure. The existing double mini-roundabout junction was reconfigured into a single, larger roundabout with widened approaches, enhanced pedestrian and cycle links, new development access roads, watercourse diversions and extensive utility upgrades.
One key engineering challenge was replacing a curved retaining wall that connected the new bridge to a second, retained structure on the same rail line. The wall sat above a shallow, skewed public sewer, ruling out piled foundations, while the adjacent bridge and live traffic limited how deep conventional foundations could go. Our ground engineering team used Finite Element modelling to design a geogrid-reinforced embankment, reducing load on the wall and allowing shallower, conventional foundations.
We also worked closely with Hampshire County Council to resolve concerns around the geometry and maintenance of the new roundabout. Our bespoke, ‘eyeball’-shaped central island provided a practical and cost-effective solution that satisfied technical, safety and operational requirements.
THE RESULT
Capacity and connectivity
The project has removed a major infrastructure bottleneck, enabling housing delivery, easing freight movement and making local journeys safer and smoother. The reconfigured junction improves traffic flow, while new pedestrian and cycle links promote more active travel. The replacement of the Victorian bridge ensures long-term resilience for a key connection between the A31 and M3.
THE LASTING IMPACT
Infrastructure that builds opportunity
This complex infrastructure upgrade is unlocking much-needed homes for the South Alton area while making a key local and regional route safer and more resilient.
Find out more about our multidisciplinary approach.
