As the only east-west motorway spanning the north of England, the M62 provides a vital national and international link across the country forming the South Pennines strategic corridor, and part of the E20 and E22 Trans European Routes. The efficient operation of this route is critical for the UK economy.
Before starting work, the project team realised that they needed to get ‘under the skin’ of specific issues facing this corridor – which contains the highest elevation of any motorway in the UK. In July, the design team from WSP and 4way consulting along with project sponsors and traffic officers from Highways England took a guided coach tour of the motorway.
During the drive through, various subject matter experts representing a range of disciplines, including highways design, environment, geotechnical and operations contextually framed the challenges and opportunities facing the 31 kilometre-length scheme. They also provided an overarching holistic appreciation of the route as it traverses some of the most difficult landforms on the motorway network. Some of the most challenging aspects include: the exposed upland Pennine Landscape, deep rock cuttings, viaducts, the Scammonden Dam, steep gradients (4%, or 1:25) and year-round harsh weather conditions such as high rainfall, strong winds and significant snowfall.
The team will also have to address the significant sensitivities associated with its natural and historic environment. These include the ecologically rare ecosystem of the upland moor and the peatland habitats flora and fauna – a recognised Special Area of Conservation for habitats and Special Protection Area for breeding birds and a Roman fort. The Pennine area has a significant public sense of ownership, with pride of the Pennine Way and its associated countryside.
In addition to these specific issues and features, the application of the latest smart motorways design philosophies – IAN 161/15 and MPI 66 – on a heavily utilised and dated network, requires the WSP design team to engage a broad range of stakeholder to enable the delivery of a safe, economic, social and environmentally minded scheme.
A follow-up visit by experts from WSP’s operations, engineering and safety disciplines helped the team visualise what site-specific solutions could look like:
- Moorland habitats: Introduce more water to the habitats – contrary to standard IAN 161 requirements, where usually outfall flows and rates are maintained. This could be achieved through innovative drainage management approaches and complimentary offsite works to direct flows upstream of the motorway. Installation of additional air quality monitoring could be utilised to look at potential nitrogen loadings and any changes that the scheme may generate, which could require mitigation interventions.
- Optimise drainage regimes: Work with Yorkshire Water to potentially increase and improve local water quality. The water supply can also be supported through pollution control an potentially reactivating and existing, but neglected, drainage network associated with the Scammomden Dam catchment area.
- Rock-cut areas: Address challenges associated with stability, drainage and a tight footprint and consider the potential to ‘optimise design’ by limiting work to only the essential areas.
- Sensitive areas: Minimise visual impacts by employing sensitive design techniques to integrate new infrastructure into the motorway corridor landscape. This could include the use of recessive paint colours, which fade into the background and are less distracting. This has been pioneered by WSP on the M1 Smart Motorways where colours were selected in conjunction with the National Trust and Historic England.
The drive through allowed the WSP team to gain insights from the network operators and invaluable local knowledge from the Traffic Officer Service representative. Ian Thompson, Senior Project Manager at WSP said, “the drive through was an invaluable experience. It allowed the team to come together and see for themselves the challenges and opportunities we are going to face as move into the design phases of the scheme. It also provided a great opportunity for us to take the project sponsor through the scheme in a live environment.”
Paul Unwin, Smart Motorways Programme Sponsor at Highways England, added "the drive through experience was invaluable. Whilst we can utilise the acknowledged e-benefits of Google Earth, Lidar and BIM etc., there is no substitute for an eyeball first hand to experience a real sense of place. We came away with a better appreciation of the dramatic scale, environmental and ecological challenges, which will assist us in better assessing the design and buildability options, risks and opportunities".