Plans 'progressing' for Glasgow's heavily delayed M8 repairs

Transport Scotland has awarded a contract to WSP UK Limited to provide technical advisory services for a permanent repair of the motorway's Woodside Viaducts.

This includes the design and implementation of a permanent solution to the structures, which form a vital part of the M8 through Glasgow.

Subject to completion of a mandatory 10-day standstill period, WSP UK Limited will undertake several responsibilities including taking the initial design work forward. 

READ MORE: Major M8 works delayed by over a year - and could cost £71m more

In May 2024, we reported how the works could cost up to £71million more than planned after being delayed by over a year.

Transport Scotland announced there had been a 'revised cost and timescale' for the motorway's 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's transport department said the contractor is working towards delivering the eastbound carriageway sooner, in Summer 2025.

The road firm also 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.

READ MORE: Parts of Glasgow's M8 to be closed for almost two months

Cabinet Secretary for Transport Fiona Hyslop said: “Carrying 150,000 vehicles daily, the Woodside Viaducts are vital to both the local and trunk road networks, and I am pleased that this contract will take us a step closer to delivering a permanent solution.

“Following inspections in 2021, significant deterioration to the viaduct supports was discovered, and temporary measures were put in place to ensure the safety of road users and allow continued use of the viaducts.

“However, the long-term plan must be to maintain and invest in the trunk road network to ensure that this section of the M8 continues to serve the wide range of transport needs and the Scottish economy for many years to come.”

A spokesperson for Transport Scotland added: "As a temporary measure to ensure the continued use of this stretch of the motorway and the safety of road users, ongoing temporary propping of the viaducts is underway.

"Once this work is complete the traffic management is expected to be removed from the viaducts, whilst the propping will enable the permanent solution to be implemented.

"We would like to thank road users and the local communities for their ongoing patience while this work is undertaken."

Ahead of planned refurbishment works on the road, investigations into the condition of the supports of each viaduct (crossheads) started in late 2020 and 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 M8 were put in place 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 props are removed.