M74 Nethan Viaduct | Bridge Refurbishment

UPDATE (03/04/25): Please be advised there will be an overnight closure (8pm-6am) on the M74 at Nethan Viaduct to allow for the scheme to progress from the centre reserve to the southbound carriageway. From 8pm on Monday 7th April until 6am on Tuesday 8th April 2025 traffic will be diverted.

M74 northbound traffic will be diverted at Junction 12 onto the B7078 and will return to the M74 via Junction 10.

M74 southbound traffic will be diverted at Junction 9 to join the B7078 and will return to the M74 via Junction 12.

Amey, on behalf of Transport Scotland, is undertaking major bridge refurbishment works on the M74 at Nethan Viaduct, south of Junction 10. The proposed programme of top-side improvements is being undertaken in five phases which entails waterproofing, concrete repair, resurfacing, expansion joint replacement, edge beam strengthening and barrier upgrade. Phases One and Two of the works to the northbound carriageway are now complete.  

Unfortunately, following an HGV incursion and other vehicle related safety issues, existing traffic management arrangements have had to be reassessed to ensure roadworker and public safety. These necessary traffic management alterations will result in an extension of the current programme with completion now projected to be Friday 8th August 2025.  

A spokesperson for Amey said: “The safety of our workforce and the travelling public is paramount when planning and delivering roadworks. This recent incursion incident highlights the importance of the speed restrictions currently in place on the M74 for everyone’s protection. Over 1,800 incursions have taken place at our sites since 2024 due to vehicles breaching safety barriers, ignoring red lights, or violating temporary speed restrictions. These incursions not only put lives at risk, but also impact the programme of our works, meaning those that do follow the restrictions are inconvenienced by further delays. We thank road users for their continued patience and understanding while these vital improvements are completed.”

Average speed cameras, installed between Junctions 9 and 11, will be in operation throughout the duration of this project with traffic speed reduced from 70mph to 30mph. This 30mph restriction is necessary to ensure the safety of personnel and members of the public given the use of narrow lanes, while also considering the high volume of HGV traffic on this route.

M74 Central Reserve

Phase Three: From Tuesday 25th February until Monday 7th April 2025, a 24-hour 1+1 contraflow will be in place to facilitate works to the central reserve. Traffic will run on the hardshoulder of the M74 in both directions with the motorway reduced by one lane, each side.  

M74 Southbound

Phase Four: From Tuesday 8th April until Friday 25th May 2025 a 24-hour 2+1 contraflow will be in place with two lanes running northbound and one southbound.  

Phase Five: From Saturday 26th April until Friday 8th August 2025 a 24-hour 2+1 contraflow will be in place with two lanes running northbound and one southbound.

Please note, every Friday between 6am and 9pm the traffic management arrangements will be altered to allow for two lanes running in both directions of the M74 at this location. Due to safety reasons, no workforce will be on site during these hours.

An overnight total closure is required at the beginning and end of each phase.  

Access for emergency service vehicles will be maintained throughout these works.  

Please note, all schemes are weather dependent and may be cancelled or rescheduled if weather conditions are not favourable.