A narrow country road in west London has been replaced with a wider road, as part of the HS2 railway project.
The HS2 railway would have needed to pass underneath the existing road that runs through the area, but as part of the agreement to build the railway, a new road wider road was built next to the old one.
Edited version of photo supplied by HS2
A new cut-and-cover Copthall Green tunnel was dug next to the old road, and a slab on top was preinstalled to carry the new road over it. The newly built 900-metre length of straight road replaced the slightly curving older Harvil Road and opened to road traffic last week.
Each carriageway – with a width of more than three and a half metres – is wider than the road it replaces, and includes 1.8 metre wide footpaths replacing a narrow single footpath that the old road had.
Skanska Costain STRABAG, the HS2 main works civil engineering contractor for the route area, carried out the works.
Skanska Costain STRABAG JV Managing Director James Richardson said: “As we complete sections of the new railway, improved local infrastructure such as Harvil Road can be used early, improving journeys through the area and supporting local communities. The section of road we have opened runs over the new Copthall tunnel, through which the new high speed trains will run.”
The pre-existing section of Harvil Road, which can be seen on maps of the area dating back to the mid-eighteenth century, was closed to traffic as the new stretch opened. It will now be removed and the land under and around it will be greened with tree and shrub planting as part of HS2’s landscaping.
It’s interesting to see the original plan for this section compared to what was built, which helps explain part of the cost increase.
The original plan (https://assets.dft.gov.uk/publications/hs2-maps-20120110/hs2arp00drrw05005issue3.pdf) used the existing Harvil Road bridge to cross the Chiltern Main Line, and built a new ‘off-line’ bridge just at the start of a much shorter realignment of the road. What is now the Copthall tunnel was also supposed to just be a simple cutting.
What was built was a longer, near dead straight realignment that required not only the crossing of the HS2 line but also a new bridge over the Chiltern Main Line and about twice the distance of road. The rail line then continues in what was originally planned as a simple cutting, but has now been amended to a green tunnel in an area where there are no dwellings or built-up areas to ‘protect’ from the line. It has to emerge short of the first dwellings it encounters due to a requirement to gain enough height to go above Breakspear Road South and the River Pinn.
It is easy to see why costs escalated from the original budget, not helped by poor reporting generally that tend to compare costings from 2012 with costs reported in 2019 figures and current day figures without mentioning which relate to which, enabling the inflation effect to be forgotten or mis-understood.