The M5 Wynhol viaduct is 50 years old


01 Dec 2023

We took a journey back in time to learn more about the construction of the South West's iconic motorway section - with one of the men who helped build it

The M5 Wynhol viaduct is 50 years old

The M5 Wynhol Viaduct is 50 years old in 2023. 84-year-old Neil Manners played a part in the landmark’s construction. Who would be better to share some working knowledge of the structure and its construction?

Retired engineer Neil has always held a personal interest in the split-level motorway, between junctions 19 and 20 in North Somerset. Recently he got the chance to learn more about how we maintain it now.

Terry Robinson, Neil Manners and Jon Durnell
Neil (centre) with National Highways’ South West Engineering Team Manager Terry Robinson (left) and Principal Geologist and Engineer,Jon Durnell (right)

We invited Neil to our operational base at Aztec West, near Bristol. He discovered the modern, digital methods we use to survey and maintain the structure. Neil said:

“As an engineer, I worked on a number of road infrastructure projects across the world and I certainly have some interest in the South West of England, having been involved in construction of the M5 Wynhol Viaduct and the Almondsbury Interchange.

“It was great to get together with the team looking after all these structures in the South West and to learn about the current engineering methods.

“Built into the slopes of the Wynhol cuttings, the M5 viaduct was a real feat of engineering and it was really interesting to see how it’s being maintained today.”

Neil Manners during construction
Neil Manners on site during construction in the 1970s
Neil Manners visits Wynhol viaduct in 2023
50 years later, Neil's back at Wynhol as our guest

Neil was also treated to an up-close and personal visit to the structure. Jon Durnell, Principal Engineer and Geologist for National Highways’ Geotechnical Asset Management team, said:

“As current guardians of the rock cuttings and viaduct, it was fantastic to meet up with Neil and fascinating to learn a little more about the construction and engineering methods and the history of this iconic landmark.

"Given the age of the viaduct, we’re going to need to do more work on the slopes and structures of the motorway in the coming years, and that’s something we’re looking at and preparing for now.

“We presented a lot of design material to Neil. It was really nice to share all the latest innovations and methods as we look forward to the next 50 years.”


Abseiling while building the Wynhol viaduct
Abseiling while building the Wynhol viaduct
Abseiling during survey in 2023
Rope work is still part of modern surveys in 2023

National Highways is responsible for nearly 50,000 geotechnical assets on its strategic road network.

In the South West, we maintain a total of:

  • 2,176 structures, including the two Severn Bridges, the Avonmouth Bridge, structures forming the Almondsbury Interchange, the Saltash Tunnel, Wynhol, Exe and Exminster Viaducts along the M5, together with a whole host of overbridges, underbridges, drainage channels and culverts
  • 6,219 earthworks assets, including embankments and cuttings such as Wynhol
  • 9,200 square miles of road, 615 miles long, comprising 70% A road and 30% motorway, in a combination of urban and rural settings.

Find out more:

How we survey the Wynhol viaduct.

Our work in the South West.