Radical Option to Close Glasgow’s M8 Viaducts Included in Consultation

A proposal to permanently close part of Glasgow’s M8 motorway has been included among options to address the ageing Woodside viaducts, which carry around 150,000 vehicles a day along the northern edge of the city centre.

Transport Scotland has launched a public consultation outlining three potential long-term solutions: repairing the existing viaducts, replacing them, or removing them entirely and diverting through-traffic onto the M74 south of the city.

The viaducts, now 55 years old, have been undergoing temporary strengthening works since 2021 due to deterioration in areas supporting the spans. The works, initially due to finish in 2023, have been extended to 2027 and are expected to cost up to £152M. During the repairs, the four-lane carriageway has been reduced to two lanes in each direction and the speed limit lowered from 50mph to 40mph.

Transport Scotland said the current propping arrangement is not a viable long-term solution, citing limited lifespan and the extensive road space taken up beneath the structure.

The removal option — which would see traffic rerouted via the M74 — is estimated to cost less than £125M and take one to two years. Repairing the viaducts is priced at £125M–£200M over one to three years, while full replacement would cost between £200M and £500M and take three to four years.

Officials have acknowledged that closure would likely have “major detrimental impacts” on traffic flows, network resilience and journey times. Industry sources suggest repair is the most realistic option, warning that removal could significantly increase congestion, particularly as the M74 is already operating near capacity.

However, campaigners advocating for the motorway’s removal have welcomed its inclusion in the consultation, arguing that reclaiming the land could support regeneration and create a more liveable city centre.

Political reaction has been divided. Some MSPs have stressed the motorway’s economic importance to the west of Scotland, while others have criticised delays and rising costs linked to the ongoing temporary works.

Public engagement events are being held in early March, with Transport Scotland inviting feedback before progressing to a permanent solution.