1.26

Object

Representation ID: 8993

Received: 01/10/2021

Respondent: Bedfordia Developments Ltd and Marcol Industrial Investments LLP

Agent: Lichfields

Comments on transport modelling evidence– for full assessment see attachment (appendix 1)
64. The transport modelling evidence presented thus far is incomplete and, in its current form, is not a sufficient level of evidence upon which to base planning based decisions. It fails to identify a number of critical elements which will undoubtedly influence the decision making process.
65. It fails to acknowledge the limitations of the modelling software in terms of how it is calibrated, how simplistic mode shift and sustainable transport is considered, that the time periods are restricted to single hours and that it is based on an assumption that current travel movements will be reinforced by traffic growth.
66. There is a significant lack of consideration being given to sustainable and active modes within the development of a mitigation strategy.
67. There is a failure to distinguish between development specific impacts and those which occur as a result of the application of an additional 10 years of traffic growth.
68. The inclusion of 10 years ‘generic’ growth is, in itself, questionable as it makes it difficult to discern development specific impacts and means that the mitigation strategy derived through the modelling is one which can only reinforce existing travel patterns and exacerbate car dependence.
69. The exacerbation results from continuing to seek to provide capacity for predicted traffic movements all of which are based on a set of assumptions around growth and trip generation which have not, themselves, been suitably tested. By not assessing the sensitivities of conclusions to certain modelling assumptions it cannot be determined how critical to the plan any of the measures identified may be.
70. There is a failure to consider the relationship between development strategy and mitigation. No regard has been given, within the isolated scenario tests, to understanding which developments are likely to rely on or contribute towards different mitigation measures. Consistent application of certain measures across all scenarios means it is not possible to determine if a development is dependent upon a measure (as a series of measures are included from the onset rather than those which are essential for a development to be delivered). Similarly, where Reference Case mitigation is not yet fully funded or permitted it should be identified as such to ensure that the reliance on mitigation of differing levels of certainty is fully identified within the assessment work.
71. The strategic model is not, in isolation, a suitable tool upon which judgements about junction capacity can be made but this is not made clear within the reporting. More refined modelling should be undertaken in areas where capacity has been identified as a constraining factor. This refined testing should consider an approach which better reflects capacity (ideally Microsimulation but, as a minimum Isolated junction modelling). It should also test how sensitive these conclusions are to other factors such as the omission of the generic TEMPRO growth and/or peak spreading and retiming of trips to allow judgements on whether mitigation is essential or desirable (i.e. if a modest change in demand negates the need for a scheme then it can, at best, only be determined as desirable).
72. Further testing should be cognisant of what it is reasonable and realistic to expect each development to deliver by way of mitigation, uniform inclusion of certain measures which are not yet permitted and/or lack funding for full delivery obfuscates the identification of development impacts, specifically when considering different development specific allocation strategies. More critically, this fails to recognise that each development brings with it unique benefits by way of mitigation strategies, especially if a foundation of mitigation is assumed in each option regardless of wether it can be delivered. Larger developments have the ability to deliver more mitigation without adversely impacts viability but this has not been considered in the modelling to date.