Deponent : Keith Alexander Buchan

Filed on behalf of : Applicant

No. of Affidavit : 1st

Date : May 1997




In the matter of an Application for Judicial Review

B E T W E E N :


- and -


- ex parte -





I, KEITH ALEXANDER BUCHAN, Executive Director of the Metropolitan Transport Research Unit, of [ ] Road, London, HEREBY MAKE OATH AND SAY as follows:

1. I make this Affidavit in support of an Application dated 6th February 1997 for Leave to Apply for Judicial Review of a decision of the North Area Plans Sub-Committee of the Mid Sussex District Council (hereinafter referred to as the "MSDC Sub Cttee") dated 7th November 1996. I refer herein to the Affirmations of Richard John Tassell dated 6th February 1997 and 22nd April 1997 filed in the above matter, and exhibits "RJT 1" to "RJT 29" thereto. The matters deposed to herein are, save where it appears otherwise, within my own personal knowledge, and are true to the best of my knowledge and belief.

2. I am currently Executive Director of the Metropolitan Transport Research Unit, an independent transport planning consultancy founded in 1988. Prior to that, I worked for local authorities in London, including the Greater London Council, where I was head of the Policy and Assessment Division. This included the strategic traffic model for London, and preparing the GLC's Transport Policies and Programme submission. I was a member of the Wood Inquiry into bans on heavy lorries in London in 1981/82, and I am currently one of the external members of the Department of Transport's Advisory Group which is revising the National Road Traffic Forecasts. I hold a Master of Science degree in Transport Planning and Management, and I am a member of the Chartered Institute of Transport and the Institution of Highways and Transportation.

3. I have been asked by the Applicant in the above matter to provide advice on the traffic implications of the proposed development for a Drive Thru McDonald's restaurant on the site of 165 London Road, East Grinstead, West Sussex by way of a conversion of the White Lion public house presently situated on that site. I am fully qualified to provide such advice and my advice is set out herein below.

4. Introduction & Scope

4.1 I am familiar with the site of the proposed development, and two of the key examples which McDonald's traffic consultant uses in his report, both of which are in West London close to major trunk roads.

4.2 I have not considered the planning implications of the development, nor the broader transport policy context within which new development takes place. I have focussed on the assertion made by the developer that the change in traffic flow will be insufficient to justify a full traffic impact assessment.

5. Potential Interference with Traffic Flow

5.1 The key concept introduced by the developer's consultant is that of "additional traffic flow". This is said to be small and therefore no traffic impact is necessary. However, the fact that traffic entering and leaving the development would have previously driven along the road without stopping does not mean that it can be discounted. Indeed, the wording in the Traffic Impact Assessment Guidelines makes no mention of additionality, simply referring to the gross amount of traffic generated by a new development (see exhibit "RJT 9").

5.2 The reason for this is clear. If a vehicle drives at a constant speed past a fixed point it occupies a measurable amount of road space for a measurable amount of time. If that same vehicle slows down and then makes a turning manoeuvre, it will occupy more road space for longer. After its visit to the Drive Thru, it must return to the road it previously used and has to enter the traffic stream from a stationary position, again using up more space than before.

5.3 The fallacy of the argument can be illustrated by assuming that 500 of the vehicles previously using the road used the Drive-Thru, but still only 20 "new" cars were attracted. In these circumstances the developer would still be arguing that there would be virtually no disturbance to traffic flow. This would quite plainly be ridiculous.

5.4 It should be noted that there are certain theoretical conditions under which the developer's assertion would hold. These are:

(i) traffic is flowing well below the road's capacity (including junctions);

(ii) there are frequent gaps in the traffic sufficient for vehicles to enter the traffic stream;

(iii) the road has no nearby junctions so that any gaps created by vehicles slowing down to leave the road can be "caught up" by the vehicles behind them.

These conditions are not met at the proposed site, particularly during the normal daytime period.

5.5 The correct analysis of whether a full impact assessment should be carried out should be based on the existing traffic conditions, and the level of traffic using the development. This should be measured as vehicle movements, since it is these which have the impact on traffic flow.

5.6 The necessity for taking this approach can be illustrated by the common situation where a development has a large vehicle flow inwards in the morning and outwards in the evening. This would be assessed in traffic terms with inward movements in the AM Peak hour and outward in the PM Peak hour. In the very specific form of development of a "Drive Thru", the inward and outward movements are by definition almost certain to be within the same hour. If the approach suggested by the developer's consultant were to be applied generally, half the traffic impact of any new development would be lost.

5.7 In this context, it should be noted that paragraph 8 of the Traffic Impact Guidelines specifically uses the phrase "traffic to and from the development" when calculating what percentage of traffic flow would "normally" cause a full impact assessment to be undertaken. This is entirely in line with the view I have taken in this advice. The Guidelines also make the point that individual circumstances may warrant a full assessment even when these percentages are not exceeded, saying,

"Although most TIAs relate to large or extensive developments it should be recognised that the movement of two milk tankers to a remote farm down a country lane may, in certain circumstances, be deemed to be unacceptable by a planning authority."

6. Conclusions

The conclusions of my advice are clear, and are as follows:

6.1 The reduction of the development's traffic flow to 1% of existing flow is only achieved by introducing the inappropriate concept of additionality, and by ignoring the existing traffic movements. Correcting for this would produce a figure of just over 6%. This would make a full traffic impact assessment "normal".

6.2 Currently on the road which would provide entry and exit for traffic to and from the development there are significant peak flows. It is located in the built up environs of East Grinstead and not in an isolated free flowing position, and there is a series of junctions close by. All this argues that the traffic situation is complex and requires full analysis if a rational decision is to be reached.

Other documents:

  • Richard Tassell's 1st affirmation
  • Richard Tassell's 2nd affirmation
  • Richard Tassell's 3rd affirmation
  • Affadavit of Ruth Gurny
  • 1st Affadavit of Keith Buchan
  • 2nd Affadavit of Keith Buchan
  • Lessons from East Grinstead
  • SWORN at )
    ) ......................................................
    This day of May 1997 )

    BEFORE ME......................................................................... ...............................
    ( A Solicitor / A Commissioner for Oaths / An Officer of the court )
    ( appointed by the Judge to take Affidavits )

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