The illustrative design prepared provided a new bridge through the centre of the interchange shown to the right of the image above and a new eastbound slip road to improve capacity. The tenderers were also provided with a VISSIM model of the new junction to demonstrate the improved traffic flows.
The project strategy was to increase capacity along the A66 and flows into the site north of the junction which was a large area of brown field land with development potential.
The tender design team was led by John Bowes who reviewed the VISSIM model and discussed what it appeared to be showing. The team were able to confirm that the queuing traffic issue had been moved to the previous junction along the A66 as the flows along the A66 and traffic merging could not be catered for. The team felt that the proposed solution would not deliver the scheme objectives.
Following a site visit John Bowes was able to identify an alternative route into the development site with a link from the previous junction and one directly from the A66. This option fulfilled all scheme objectives and was estimated to provide a 15-20% saving on the £12m scheme estimate.
Unfortunately on this occasion the contractors tender was not successful. However, the alternative layout was shared with the successful contractor and a solution similar to that described above was constructed.
