Changes to the Lower Thames Crossing planning application have added £362.5M to the final estimated cost of the project.
Highways England unveiled changes to its planning application in June. Changes have been made in regard to traffic management, air quality control, noise and vibration, as well as the impact of the new crossing on the environment and landscape.
They have been added to the project’s development consent order application after Highways England was forced to pull its original plans following feedback from the Planning Inspectorate in November last year.
The additional costs are revealed in the Office of Rail and Roads (ORR) annual assessment of Highways England performance.
The ORR report adds: “The main cause of the forecast total outturn increase [on] the Lower Thames Crossing scheme [is] largely due to scope changes to meet safety/environmental requirements and address scope uncertainty”.
The cost increase is the largest forecasted cost hike on any Highways England scheme.
Despite the additional costs, it is believed that the project is still estimated to come in within its projected cost window of £6.4bn and £8.2bn.
The ORR report also reveals that Highways England is now concerned that construction of the tunnel between Essex and Kent is at risk of delays due to revisions in the planning application.
Highways England plans to submit a new application later this year to restart the consent process. If given the green light, construction is still expected to start in 2024 and take around six years, leading to a revised road opening date between 2029 and 2030.
Despite the setback to the planning application, Highways England has continued its procurement for the project.