Trunk Road Improvement Schemes (Hansard, 6 December 1996)

§ Mr. Watts

[holding answer 25 November 1996]I have asked the chief executive of the Highways Agency to write to my hon Friend.

Letter from Lawrie Haynes to Mr. Robert Key, dated 6 December 1996: The Secretary of State for Transport has asked me to reply to your recent question asking if he will list the trunk road improvement schemes which he has reassessed following the recommendations of the Standing Advisory Committee on Trunk Road Assessment, and indicate for each such scheme the impact on traffic induction forecasts and on economic appraisals. We are carrying out SACTRA assessments for all schemes in the National Trunk Roads Programme. So far, 63 schemes from the 1996 Trunk Roads Programme have been assessed. The schedule classifies schemes into simple, intermediate and complex categories. Simple schemes are those where induced traffic effects are not considered to be significant and no further traffic or economic assessment is required. They are listed at Annex A. Intermediate schemes generally require a more flexible test to assess induced traffic and economic effects. Complex schemes are assessed in the same way as intermediate schemes but also require further detailed analysis. The further assessments for intermediate and complex schemes are being undertaken as part of general scheme preparation. Results are being produced for key stages such as public consultation and publication of draft Orders. Completion of all the assessments will, therefore, take some time. The table at Annex B shows the results for those schemes which have had detailed assessments completed. Annexes C and D are lists of the schemes in the intermediate and complex categories respectively for which the further assessments have yet to be carried out. The assessments indicate that the volume of additional traffic induced by schemes is generally less than 10 per cent., and in many cases below 5 per cent. Nevertheless, there can be significant variations on this; for example where substantial new development follows a road opening. The economic assessment process for induced traffic is still being developed and improved. For now, where induced traffic is likely to be a significant factor, we are undertaking sensitivity tests based on assumptions that provide an extreme test of scheme economics. For example, in some cases sensitivity has been tested with significantly higher volumes of induced traffic than are expected. I am pleased to say that, so far, although there are some significant reductions in Benefit Cost Ratio, none of the schemes assessed have failed the tests, even where unrealistically high levels of induced traffic have been assumed, and all have remained good value for money. Annex A: National trunk road schemes—preliminary SACTRA classifications Simple

A2 Lydden—Dover Improvement
A205 Catford Town Centre Improvement
A303 Winterbourne Stoke Bypass
A303 Ilminister Bypass Improvement
A303 Sparkford—Ilchester improvement
A30/A303 Marsh Honiton and A35 Honiton Eastern Bypass
A35 Tolpuddle—Puddletown Bypass
A417 North of Stratton—Nettleton Improvement
A419 Latton Bypass
A419/A417 Cirencester and Stratton Bypass
A428 Norse Link Road
A43 Geddington Bypass
A564 Doverridge Bypass
A595 Parton—Lillyhall Improvement
A6 Rothwell—Desborough Bypass
A65 Hellifield and Long Preston Bypass
A65 Manor Park Bends Improvement
A69 Haltwistle Bypass
M23 Jns 8–9 Widening

Note:

The classifications shown above are preliminary and may change as a result of further detailed analysis.

Annex B: National trunk road schemes—preliminary induced traffic appraisal
Scheme	Reduction in benefit to cost ratio Per cent.	Amount of induced traffic Per cent.
A13 Ironbridge-Canning Town Improvement	37	5
Al3 Movers Lane Junction Improvement	23	5
A13/A112 Prince Regent Lane Junction Improvement	38	5
A13/A117 Junction Improvement	38	5
A 19 Norton-Parkway Interchange Improvement	2	5
Al(M) Alconbury-Peterborough	21	5
A249 Iwade Bypass-Queenborough Improvement	no change	¹25
A27 Worthing-Lancing Improvement (now withdrawn)	30	5
A30 Honiton to Exeter Improvement	30	10
A34 Newbury Bypass	17	10
A36 Salisbury Bypass	15	5
A453 Clifton Lane Improvement	21	5
A556(M) M6-M56 Link Improvement	no change	5
A6(M) Stockport North/South Bypass	[...]5	5
M40 Jn 1A-3 Widening	41	5

The reduction in Benefits to Cost Ratio (BCR) compares the induced traffic appraisal with the original fixed trip matrix evaluation.

The amount of induced traffic is an approximate figure based on the number of additional trips induced by the scheme compared with the do-minimum trip matrix.

¹Indicates induced traffic includes major new development dependent on the scheme.

Annex C: National trunk road schemes—preliminary SACTRA classifications

Intermediate
Al20 Stansted-Braintree Improvement (S272)
A1(M) Ferrybridge-Hook Moor Improvement
A21 Lamberhurst Bypass
A259 Bexhill and Hastings Western Bypass
A2/A282 Dartford Improvement
A3 Hindhead Improvement
A34 Chieveley/M4 Jn 13 Improvement
A40 Western Circus Junction Improvement
A43 Moulton-Broughton Improvement
A43 Silverstone Bypass
A43 Whitefield Turn-Brackley Hatch Improvement
A564 Derby Southern Bypass Contract A
A6 Clapham Bypass
A6 Great Glenn Bypass
A6 Rushden and Higham Ferrers Bypass
A63 Castle Street Hull Improvement
MI-A1 Link Road Lofthouse-Bramham
M1 jns 25–28 Widening
M11 jn 5 North Facing Slip Roads
M2 jns 1–4 Widening
M25 Terminal 5 Spur (Heathrow)
M4 jns 8(9)–10 Widening
M6 Jns 11A–16 Widening
M6 Jns 16–19 Widening
M63 Jns 6–9 Widening

Note: The classifications shown above are preliminary and may change as a result of further detailed analysis.

Annex D: National trunk road schemes—preliminary SACTRA classifications

Complex

Al Gateshead Western Bypass
M1 Jns 10–14 Widening
M1 jns 6A–10 Widening
M25 jn 12–15 Widening
M25 jn 15–16 Widening