Butt’s Bridge – Highway Improvements

Unlocking South Alton housing meant upgrading the local highway network, including replacing a narrow Victorian era bridge over the A339 and redesigning the congested Butts Bridge junction.

We delivered a range of interdisciplinary services, from project management and procurement support to transport planning and civil engineering.

Engineering bold and buildable solutions

Leading the project from early planning through to delivery, we helped navigate complex technical challenges and kept a wide group of stakeholders moving together.

The works included demolishing the Victorian brick arch railway bridge and replacing it with a 32-metre weathering-steel skew span. The existing double mini roundabout was reconfigured into a single larger roundabout with widened approaches, safer pedestrian and cycle links, new access roads for future development, watercourse diversions and extensive utility upgrades.

One of the key challenges 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 foundations could go. Using finite element modelling, our ground engineering team designed a geogrid-reinforced embankment that reduced load on the wall and allowed for shallower, more practical foundations.

We also worked closely with Hampshire County Council to resolve concerns around the geometry and long-term maintenance of the new roundabout. Our bespoke “eyeball shaped” island offered a practical, cost-effective solution that met safety, operational and technical needs.

Capacity and connectivity

The project has removed a major bottleneck, unlocking housing delivery, easing freight movement and making everyday journeys smoother. The reconfigured junction improves traffic flow, while the new pedestrian and cycle routes encourage more active travel. Replacing the Victorian bridge also strengthens the long-term resilience of a key link between the A31 and the M3.

Infrastructure that builds opportunity

This complex upgrade opens the door for much-needed homes in South Alton and makes a vital local and regional route more reliable for years to come. It shows how thoughtful engineering and steady coordination create infrastructure that works for the communities it serves.