M8 roadworks: EIR release

Information requested

The closure of the 2 slip roads on the M8 (16 and 17, I think) has been in force for well over 2 years. It's created a miserable commute to work for 1000s of people, but light was at the end of the tunnel, I'd checked, and it was due for completion at the end of this month. I've just checked again, and it's now got a completion date for March next year! So I have some questions.

• What is it that is being done?
• Why was it going to take over 2 years to complete?
• What makes it such a complicated job?
• Why has the completion date been put back a further 6 months?
• How much was it originally budgeted to cost?
• How much will it now cost?

Response

As the information you have requested is ‘environmental information’ for the purposes of the Environmental Information (Scotland) Regulations 2004 (EIRs), we are required to deal with your request
under those Regulations. We are applying the exemption at section 39(2) of the Freedom of Information (Scotland) Act 2002 (FOISA), so that we do not also have to deal with your request under FOISA.

This exemption is subject to the ‘public interest test’. Therefore, taking account of all the circumstances of this case, we have considered if the public interest in disclosing the information outweighs the public interest in applying the exemption. We have found that, on balance, the public interest lies in favour of upholding the exemption, because there is no public interest in dealing with the same request under two different regimes. This is essentially a technical point and has no material effect on the outcome of your request.

Response to your request

I have numbered your queries for ease of reference.

1. What is it that is being done?

The M8 Woodside Viaducts are a vital element of Scotland’s motorway network. The Viaducts consist of two structures carrying the M8 between junctions 16 (Craighall) and 17 (Charing Cross). Following investigation works on the viaducts undertaken in late 2020/ early 2021, the condition of the concrete supports was deemed to be in worse condition than anticipated. As a result, lane and speed restrictions were put in place on the M8 between Junctions 16 and 17. The closure of the M8 on and off-slips between the junctions is in place to ensure a reduced traffic load is exerted on the viaduct’s supports allowing the M8 to remain open to two lanes. The structural repair works are ongoing below the structure, they are not visible from the M8 and are extensive and complex.

The works involve temporarily propping the affected supports and carrying out repairs to the elements which support the deck. The temporary propping will support the bridge deck, thus removing the load from the supports and allow repair works to take place. Once all temporary props are in place and the structural load from the bridge decks are transferred from the existing supports, lane restrictions on the M8 can then be removed. More information on the project and current updates can be found on the project website:
https://swtrunkroads.scot/major-works/m8-woodside-viaducts-j16-j17/.

2. Why was it going to take over 2 years to complete? What makes it such a complicated job?

There are a number of factors contributing to the complexity of this project. These include:

• Managing traffic both on the M8 and on the extensive road network below it;
• Maintaining pedestrian/cyclist access under the viaducts;
• The presence of a number of public and private utilities, several of which cannot be relocated away from the area i.e. gas, water and electrical services;
• The presence of the SPT subway tunnels to the west end of the viaducts;
• The age and nature of the viaducts, requiring bespoke design and construction solutions;
• The design of the propping solutions running concurrently with the construction phase leading to a unique project environment; and
• Access to and within the site for materials and plant.

Liaison is ongoing with relevant stakeholders to minimise disruption, whilst the viaduct works are ongoing.

3. Why has the completion date been put back a further 6 months?

Each support location on Woodside Viaducts is different in size, depth and orientation, with the number of buried services and ground conditions varying at each of these points. These factors need to be carefully considered and thus designs are different for each location. Accordingly, the completion date is subject to change as the design develops, which could accelerate or extend the construction programme depending on complexity.

4. How much was it originally budgeted to cost?
The information you have requested is available from Costs of investigative and remedial works on M8 Junction 16 and 17 (Woodside Viaduct): EIR release - gov.scot (www.gov.scot).

Under regulation 6(1)(b) of the EIRs, we do not have to give you information which is already publicly available and easily accessible to you in another form or format. If, however, you do not have internet access to obtain this information from the website(s) listed, then please contact me again and I will send you a paper copy.

This early estimate excluded VAT, risk allowances and other commercial costing mechanisms such as Optimism Bias.

5. How much will it now cost?

The estimated cost for propping and enabling works is currently £98.7m excluding VAT, risk allowances and other commercial costing mechanisms such as Optimism Bias. Costs are reviewed regularly and are subject to change due to the unique nature of the works.

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