The construction of a new bridge carrying the A43 over the future HS2 railway near Brackley has reached a significant milestone, with traffic now flowing in both directions across the newly completed structure.
The busy dual carriageway, which connects Oxford, Brackley and Northampton while providing a key link between the M40 and M1, reopened on Sunday evening following two consecutive weekends of carefully planned traffic management and road closures.
The completion of the complex realignment marks a major step forward in HS2's plans to take the high-speed railway beneath the A43. With vehicles now running across the new bridge, engineers can begin excavating the cutting that will eventually accommodate the railway line underneath.
The project has been years in the making. Preparatory work began in 2023 when HS2, working alongside National Highways, realigned sections of the A43 to create enough space between the carriageways for the bridge construction works.
Using an innovative top-down construction method, engineers installed piled foundations extending 52 metres into the ground before constructing the supporting pile caps and bridge piers. The 66-metre-long bridge deck was then assembled, with seven huge steel beams lifted into position to support the concrete road deck above.
To minimise disruption on one of Northamptonshire's busiest roads, the final phase was delivered over two weekends. Each carriageway was closed and diverted onto the new bridge sequentially, allowing traffic to continue flowing in one direction while work took place on the other.
The programme was also carefully timed to avoid clashes with the Formula One British Grand Prix at nearby Silverstone earlier this month.
HS2 Ltd’s Head of Delivery Luis Gonzalez said:
"The A43 is a busy route between Brackley and Northampton and I’d like to thank drivers for their patience over the last two weekends, while we safely realigned the road over the new bridge."
“With the traffic flowing over the top, we can focus on the next part of this complex multi-stage project – excavating the cutting that will take the railway under the road.”
The section of HS2 running through the Brackley area forms part of the 50-mile (80km) route being delivered by EKFB – a joint venture comprising Eiffage, Kier, Ferrovial Construction and BAM Nuttall – working alongside design partner ASC, a collaboration between Arcadis, Setec and COWI.
Throughout construction, EKFB, Kier Transportation and National Highways have worked closely together to maintain traffic flow while progressing one of the project's most technically challenging highway interfaces.
The A43 milestone is one of several recent transport infrastructure achievements across Buckinghamshire and Northamptonshire. Over the past six months, six local roads and crossings have been returned to service, including the A4421 Buckingham Road, Edgcott Road near Quainton and Oatleys Road, which crosses the Turweston Green Bridge near Brackley.
EKFB’s Project Director, Tony Wehby, said:
"Completing the construction works on the A43 marks a significant milestone for the EKFB team and its supply chain partners. This completion now allows us to the remove material from underneath the road and press ahead with our earthworks programme in this area.
“Thank you to EKFB’s highways and traffic teams, National Highways, Kier Transportation and the construction team for the world-class operation, not only on the opening on the A43 but also the opening of six other roads around the Brackley area. Not only have we limited the disruption for our local communities and road users, but we have done so in a considerate and safe way.”
National Highways also praised the collaborative approach that helped keep disruption to a minimum throughout the works.
National Highways Head of Network Planning and Development, Ian Doust, said:
"An infrastructure project on this scale will inevitably cause some disruption but our priority is reducing the impact on the people who use our roads as much as possible.
“Thanks to some innovative traffic management, cutting edge engineering and close collaboration between National Highways, HS2 and their partners, we have been able to do that.
“It is very satisfying to see the traffic now flowing in both directions on the new bridge and the progress being made on this complex project.”
The A43 bridge forms part of the wider HS2 programme, which includes more than 500 bridge and viaduct structures ranging from footbridges and wildlife crossings to major motorway overpasses and the landmark Colne Valley Viaduct.
Once complete, HS2 will provide high-speed rail services between London and Birmingham while creating additional capacity on the existing West Coast Main Line for local and freight services.
Despite significant progress across the route, substantial work remains on the 140-mile railway between London and the West Midlands. HS2 Chief Executive Mark Wild continues to lead a comprehensive reset of the programme aimed at improving delivery efficiency and reducing overall project costs.
Image credits: HS2
