Long-running M8 Glasgow Woodside viaducts roadworks extended by another two years

The Scottish Government agency said “previously unknown challenges” would extend the project which has narrowed the M8 from four to two lanes in each direction over the Woodside viaducts on the northern edge of the city centre for the last four years.

The stretch is used by 150,000 vehicles a day, where a 40mph speed limit has been force during the works.

Transport Scotland said restrictions on the eastbound carriageway were now due to be lifted in autumn 2026 and on the westbound carriageway in the the second half of 2027.

However, it said the revised dates were “subject to no further adverse conditions or unforeseen challenges”.

The Scotsman revealed in May that the roadworks were expected to continue until 2027 rather than finished this year.

Transport Scotland said the project had been “continuously hampered by inaccurate records of utility apparatus” - pipes and cables.

It said progress had been slowed by a sewer deep underground beside a Glasgow Subway tunnel at the western end of the viaducts being discovered in a different location than expected.

‘Unusual level of complexity’

Contractors Amey also found that strengthening triangular crossheads which support the viaducts at their western end, along with associated propping steelwork, had been more complicated than anticipated.

Transport Scotland said the need to avoid disturbing the Subway tunnels had “introduced an unusual level of complexity” and delayed propping up both the eastbound and westbound viaducts.

But it said the cost of the project to refurbish the 55-year-old viaducts remained between £126 and £152 million.

Scotland-based road safety consultant Neil Greig said: “Whilst M8 drivers will sympathise with some of the complexities involved, it does beggar belief that it’s taken so long to identify and deal with them.

“The ongoing cost of delays, pollution and unpredictable delivery and journey times to individuals and the Scottish economy seems to be simply ignored by Transport Scotland.

“This stretch of the M8 is a key pinch point in the central Scotland motorway network. Drivers need to believe someone is actually giving it the priority it needs because at the moment it feels never ending”.

‘Urgent action’

Glasgow Labour MSP Pauline McNeill, who has campaigned on the issue, said: “Notwithstanding the discovery of new obstacles and problems, I still question why it has taken four years to discover the extent of the work needed for this project.

”The completion date has already slipped from 2023 to 2024, and now to 2026–27. The public deserves regular updates - and urgent action to complete these works without further delay.”

Transport Scotland director of major projects Lawrence Shackman said: “I understand the completion of these works is keenly anticipated by M8 road users and the local community, not least to lessen the impacts from its construction.

Scotland relies on its transport links - stay informed with our Transport newsletter

“Transport Scotland continues to robustly engage with Amey to deliver the work as quickly and safely as possible.

“Despite facing significant challenges, the project has made substantial progress, with temporary props installed at 13 pier locations out of 23.

‘Significant challenges’

“In addition, ten of the temporary props have been jacked to assist with supporting the carriageway and taking the load.

“The location of the motorway through a busy, built-up city has meant this project has always been technically complex and presented a number of challenges, notwithstanding dealing with 23 supports that all require individual propping designs to take account of the varying column heights, span lengths and widths.

“The project has been continuously hampered by inaccurate records of utility apparatus as well as the recent discovery of an uncharted sewer buried deep underground leading to delays and additional work. Amey continues to face significant challenges.”