The NPPF: A Digest
Promoting sustainable transport
“58. …The effect of paragraph 111 of the Framework is to require a developer to produce a transport assessment which is sufficiently satisfactory for a conclusion about the severity of the impact to be reached. If that is done, and the impact is less than unacceptable or severe, there is no highway basis in the Framework for refusing permission in a “tilted balance” case. But if the transport assessment is too deficient in that respect for a judgment to be reached, paragraph 109 cannot assist. Otherwise, it would be open under the Framework for a developer to come forward with no sound work, and require the Council to prove the serious impact. That is not how the two paragraphs are meant to work. Both the Framework and the development plan start from the same premise, that the developer must have produced a sound and reliable transport assessment.”
R (Hawkhurst Parish Council) v Tunbridge Wells BC  EWHC 3019 (Admin), James Strachan KC
Alistair Mills appeared for the Claimant
“110. Read together, the natural and ordinary meaning of paragraphs 108 and 109 of the NPPF are clear. In assessing an application for development, the decision-maker needs to ensure that significant impacts of development on the capacity and congestion of the highway network can be cost effectively mitigated to an acceptable degree, but there should only be a refusal on that basis if the residual cumulative impacts (which includes taking account of any mitigation that is proposed by the developer) on the road network would be severe.
- There is no definition in the NPPF of what will constitute “severe” residual cumulative impacts for these purposes. Inevitably a qualitative term of this kind used in the NPPF necessarily calls for the exercise of judgment on the part of the decision-maker. As with all such judgments, they will be subject to the normal constraints that the principles of administrative law impose. As is well-established, those include the need to take into account relevant considerations, to have sufficient information to be able to make a lawful assessment and for the judgment to be rational in a Wednesbury sense. But ultimately the judgment itself is one of judgment for the decision-maker. It may well be a matter on which reasonable people can disagree, but that is not a basis for impugning the decision reached.
- I agree with the general thrust of Mr Mills’ submission that a judgment of this kind – namely whether there are severe residual cumulative impacts on the traffic network from a development – will often be one which will require some technical information for the assessment to be made. In this respect, it is relevant to consider paragraphs 108 and 109 of the NPPF alongside paragraph 111 of the NPPF:
“All development that will generate significant amounts of movement should be required to provide a travel plan, and the application should be supported by a transport statement or transport assessment so that the likely impacts of the proposal can be assessed.”
- The corollary of what is stated in the first part of that paragraph is that development which will not generate “significant” amounts of movement is not necessarily expected to be supported by a transport statement or transport assessment. Here, once again, the NPPF requires a judgment from the decision-maker as to what will constitute “significant” amounts of movement. It is inherent in what is stated that if the decision-maker takes the view that the development is not one which will generate “significant” amounts of movement, then it may not require a transport statement or transport assessment to provided in support of the planning application itself. This further illustrates the role of judgment in the exercise required in this part of the NPPF.
- It is also relevant to note (as both Ms Thomas and (in more detail) Mr Cannock pointed out) that paragraph 111 of the NPPF is referring to two different types of transport document for these purposes: a transport statement and a transport assessment. Further guidance is provided in the Government’s national online Planning Practice Guidance about the differences between these two documents. Paragraph 004 (Reference ID: 42-004-20140306) states:
“… Transport Assessments are thorough assessments of the transport implications of development, and Transport Statements are a ‘lighter-touch’ evaluation to be used where this would be more proportionate to the potential impact of the development (ie in the case of developments with anticipated limited transport impacts).
Where the transport impacts of development are not significant, it may be that no Transport Assessment or Statement or Travel Plan is required. Local planning authorities, developers, relevant transport authorities, and neighbourhood planning organisations should agree what evaluation is needed in each instance.”
- Accordingly, whilst both a Transport Assessment and a Transport Statement will be directed at assessing the likely impacts of development where significant movements are anticipated and, ultimately, whether there will be severe residual cumulative impacts (after mitigation is taken into account), a Transport Statement is intended to be a ‘lighter touch’ evaluation of the likely impacts. Again, this is an area where the exercise of judgment will be in play as to what type of document is required in any particular case.”