Major roadworks on Glasgow's M8 delayed by over a year

Transport Scotland has announced there has been a 'revised cost and timescale' for the motorway's M8 Woodside Viaduct temporary propping works.

The works - which started in 2021 and were to run until late 2024 - are now expected to be fully completed in early 2026.

However, the Scottish Government transport department has said, the contractor is working towards delivering the eastbound carriageway sooner, in Summer 2025.

On top of that, Transport Scotland has revealed the cost range for the project is now £126million to £152million.

Previously, the Scottish Government revealed in 2023 estimated cost of the propping works was £81.6million.

Revealing the time extension and cost hike, Transport Scotland has said ongoing design and construction works has revealed the extent and complexity of the measures required to temporarily prop the viaducts and return the M8 to full traffic capacity.

Lawrence Shackman, Transport Scotland’s Director of Major Projects, said: “The M8 Woodside Viaducts are a vital element of Scotland’s motorway network, carrying 150,000 vehicles daily.

“Our Principal Contractor, Amey, has been delivering this highly complex work on behalf of Transport Scotland while ensuring this busy section of the M8 motorway remains open.

“The ongoing temporary propping works are challenging due to the varying ground conditions and site constraints, including the presence of a plethora of public utilities as well as the Glasgow subway underground tunnels.

“Once the structure is fully propped, lane restrictions on the M8 can be removed.

“The construction programme expects the eastbound viaduct lane restrictions to be removed in summer 2025, followed by the removal of the westbound viaduct lane restrictions in early 2026.”

Investigations into the condition of the supports of each viaduct (crossheads) started in late 2020, early 2021.

Engineers found that the supports of each viaduct were in worse condition than anticipated.

In March 2021 it was decided it was necessary to prop up suspended spans for more extensive repairs to be done.

It meant lane closures and speed restrictions on the M8n and roads underneath the viaduct closed to allow work to be carried out from below.

The works involve propping the affected supports and carrying out repairs to the elements which support the deck.  

The work involved excavation to foundation level, and specially manufactured steel supports erected with jacks to remove load from the supports.  

Once jacking has taken place, repairs of the supports are carried out, and the jacks and propping removed.