Costs on a major road improvement project have risen from £250M to almost £400M due to the “challenging nature” of engineering the scheme, including the unexpected exhumation of 19,000 skeletons.
Highways England has revealed that initial cost estimates for the A63 Castle Street scheme in Hull, which aims to reduce traffic congestion and improve access to the Port of Hull, have risen from an initial estimate of £250M put forward in 2010 to £392.5M.
Councillor Martin Mancey, who is responsible for Hull City Council’s transport portfolio, said he was not surprised costs have increased but stressed the importance of the project to Hull’s economy.
He said: “I’m not surprised that the cost has one up. It is a lot of money but from an entirely different perspective, the improvement of the road is absolutely essential to the economic prosperity not just of the city but of the region.
“It links the Port of Hull to the motorway network, so its economic significance can’t be overstated.”
Part of the cost increase is due to a better understanding of conditions at Trinity Burial Ground, which holds 44,041 bodies and is in the path of a new slip road. Highways England project manager for the scheme Jimmy Holmes told New Civil Engineer that although engineers thought around a third of the bodies would need to be exhumed, the final figure is 19,000.
He added: “We knew that the scheme needed to go through the burial ground, but it is an old burial ground which closed in 1860 and we didn’t know how many bodies we were dealing with.”
Ground investigations had to be carried out to determine whether any of the bodies at Trinity Burial Ground were below the water table, which would have required individual sheet piled walls to be installed at the burial ground. However, all of those buried are above the water table, meaning archaeologists can excavate as usual.
Soft ground conditions, unexpected utility cable finds and challenges posed by two Grade II listed buildings on the A63 route have all helped push the cost up, while the £11.5M Princes Quay footbridge, which has experienced delays, was not factored into the original cost. The bridge was due to open in time for Hull’s role as the UK City of Culture in 2017 but work will not start until October this year.
However, Holmes stressed the Department for Transport (DfT) still believes that the project respresents value for money for the taxpayer.
He said: “It’s gone through a rigorous value for money assessment and it’s still showing that even at an increased cost of £392M it’s delivering value for money to taxpayers.”
The excavation at Trinity Burial Ground is the largest exavation of its kind outside London. The skeletons must be moved to an unaffected part of the burial ground before construction work can start at Castle Street in March 2020.
Two new bridges are to be built over the A63 as part of the scheme, and a new junction will be created. The project was first considered in 2010 and has been in preparation since it was granted funding in 2013.
An application for a development consent order will be made in July this year. Work on the A63 Castle Street upgrade is expected to finish in 2025.
A spokesperson for Highways England said: “The Castle Street scheme is a major and complex project which presents a number of unique engineering challenges.”