A1 Black Cat Roundabout
Case reference EIR2025/01082
Received 3 June 2025
Published 20 August 2025
Request
I would like to request the following information:
1. Was a realignment of the A1 northbound to straighten out the S-bend fully considered as part of the project?
2. If so, what were the specific reasons—financial, environmental, engineering or otherwise—that led to this option being rejected?
3. What safety impact assessments were conducted for the retained S-bend configuration, both pre- and post-closure of side road accesses?
4. What modelling or assumptions were used to determine that the current alignment met the scheme’s safety and traffic flow goals? I believe this is a fair and reasonable concern, especially given the intention of the project to improve road safety and journey times along this critical corridor.
Response
1. Was a realignment of the A1 northbound to straighten out the S-bend fully considered as part of the project?
Works to the A1 between the scheme and Tempsford, including improvements to the alignment near Kelpie marine, are outside the scope of A428 Black Cat to Caxton Gibbet
2. If so, what were the specific reasons—financial, environmental, engineering or otherwise—that led to this option being rejected?
These reasons were not considered as this work was out of scope.
3. What safety impact assessments were conducted for the retained S-bend configuration, both pre- and post-closure of side road accesses?
The area not assessed as it wasn’t part of the scheme.
4. What modelling or assumptions were used to determine that the current alignment met the scheme’s safety and traffic flow goals?
There is no modelling requirement for this location as it is not part of the scheme. However, it should be noted that the scheme will not change the speed limits at this location, therefore retaining the 60mph pre-scheme limit. There has also been the removal of the at grade entrance to Kelpie Marine which has been replaced by an over bridge.
Advice and Assistance
We have answered the specific points raised above, but fundamentally the inclusion of a realignment of the Kelpie bends was not part of the scope of the scheme issues to us by the Department for Transport. National Highways is given a remit to develop schemes based on a set of strict criteria and in the example of the A428 Black Cat to Caxton Gibbet this included a particular area North to South and East to West of which the A1bends between the North of Tempsford and the South of Kelpie Marine where not part of this as they are beyond the southern extent of the scheme.
The Department for Transport and therefore National Highways has a finite amount of money allocated to it by central government and this must be spent according to the greatest need, this need will be decided using a number of different factors such as Economic benefit, journey time reliability, Safety, environmental and many other considerations, there are many schemes that are desired and have good merit but the pressures on available financing mean that many are not able to be undertaken at all, are delayed for future periods or are fixed in their scope. The A428 is an example where the scheme had a fixed remit, and while there are of course arguments for including further aspects, such as the one you have highlighted, it is not possible due to the funding available, it is a case of ensuring as much is done that meets the benefits set out earlier in this email.
The area of the A1 Northbound you refer to would be quite complex from an engineering perspective as it spans a river and a floodplain and this in turn would incur a fairly large amount of additional funding to be sought, which for the reasons set out above is likely why it was not part of the project scope. As with any scheme there has to be a decision of where to draw the line as of course there would always something else that has the potential to be included.
Documents
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