A83: Evaluation of Jacobs’ study and recommendation


Transport Scotland presented the members of the A83 Taskforce with the draft report by commissioned consultants, Jacobs, during its last meeting on 14th December.

We reported on the emergence of the report and made it available as a download, leaving our evaluation of it until we had time to analyse it methodically – which we have now done and publish on a day when the A83 is yet again on landslide alert.

The first thing to be said is that it is virtually unheard of for consultants not to deliver what they are hired to deliver – and that is the case in this instance. It can be shown to be so by the internal contradictions in the report’s own evidence, demonstrably distorted and managed to appear to support its unsurprising and flawed recommendation.

As anyone is aware, who has read the report or has read brief accounts of its summary conclusions in the print media, the consultants first considered six possible approaches to a permanent solution to the vulnerability of the A83 to closure through landslides.

The options

In summary, these six options were:

  • more debris netting and more drainage with the planting of vegetation on the hillside;
  • a debris shelter over the road, allowing landslip debris to flow over the shelter, leaving traffic unimpeded;
  • a new 1.5km two lane single carriageway section parallel to the current A83, built on a viaduct, allowing debris to run below it;
  • a new single carriageway in the valley below the A84, then entering a 1.9km long twin bore tunnel at a maximum 4% gradient, ‘rejoining the existing A83 in the vicinity of Loch Restil’;
  • a new single carriageway in the valley below the A83, climbing steeply at a maximum gradient of 8% around the top of the glen before passing west of the Rest and Be Thankful car park and rejoining the existing road before Loch Restil;
  • a new 4.0km single carriageway on the opposite hillside to the current A83 and following the line of existing forestry tracks;

The process

As the report describes, three options were discounted after initial appraisal – the debris shelter; the tunnel and the hill climbers delight of another set of chicanes up to the car park.

The other three were then evaluated against ‘a more detailed economic appraisal’ – these were more debris netting with more draining and planting; the viaduct section; the section following the hillside forestry track on the far side of the valley.

The decision

The consultants’ recommendation is for the option of adding more debris netting, more drainage and the planting of vegetation on the troubled hillside.

This is, as everyone has, of course, noticed, the cheapest of the six options considered.

Why the recommended option is incontrovertibly the wrong one

In the detailed descriptions of each of the options in the body of the report, the chosen option is the ONLY one of  the six that cannot be said to reduce to NEGLIGIBLE the possibility of the A83 being closed again with landslip debris.

The best that can be said of this option is that it can be ‘expected to significantly reduce the frequency of occurrence of landslide debris reaching the A83 Trunk Road at a much lower cost than the other options.’

No definition is given – or could be given – as to what ‘significantly reduce the frequency of landslide debris reaching the A83′ actually means. Nowhere, in this report or elsewhere, has it ever been stated what weight of debris material travelling at what speed the debris netting can take before being overcome.

At another point in the detail of the report, this chosen option is described as ‘offering ‘a significant step-change [Ed: NOT a permanent solution] in the landslide hazard reduction for the A83 Rest and Be Thankful.’

Moreover, the report declares that: ‘The planting of vegetation may also help contribute to this strategy though the beneficial effects of vegetation would be realised during a period around 15 to 35 years after planting.’ [Ed: our emphases]

The report goes on to say that: ”The Emergency Diversion Route being brought into use by Transport Scotland would be required until the proposed measures had provided sufficient protection to the A83.’

Since the proposed measure in the recommended option includes the planting of vegetation on the insecure hillside, the emergency diversion route would therefore be required in use for between 15 and 35 years, until the vegetation had delivered its potential beneficial impact.

Then, because it cannot reduce the risk of landslides closing the road to more than a ‘substantial step change’, the recommended solution will still see the road subject to hazard warnings of increased risk of landslides in very wet weather or melting heavy snow.

The necessary frequency of these alerts – as detailed below under ‘The major distortion’ – is the real economic killer for Argyll.

The high degree of uncertainty of access to the area dictated by the fragility of its only major point of road entry does untold damage to its economic stability and development.

The major distortion

Amongst many serious failures in the report – of factual accuracy and of conveniently inadequate interpretation of evidence [the most glaring of which are listed further below], there is one standout manipulation.

The selection of the cheapest option, supported by Transport Scotland, is buttressed by the shrugged claim that the A83 was only closed for three days this year [in any case it saw four dates in six months with closed notices]. The implication of this reductive claim is: ‘You can’t expect us to spend serious money for the sake of three days?’

The key fact is not the number of absolute closures but the number of days when this road is under formal warning of increased risk of landslides – and therefore MAY close at any moment.

For Argyll has, from the 1st July 2012, meticulously logged and published every occasion on which Transport Scotland has issued these warnings of increased risk of landslides on the A83 at Rest and Be Thankful.

To date those notices have appeared on no fewer than 54 dates, four of which [noted below] saw the road actually closed with landslides.

The breakdown has been:

  • July: 9 dates
  • August: 18 dates – including three consecutive dates with ‘closed’ notices due to a major landslide of 1,200 tonnes – 1st, 2nd and 3rd August, the middle of the tourist season]
  • September: 5 dates
  • October: 10 dates
  • November: 7 dates – including one,19th November, with a closure due to landslide
  • December – to date: 5 dates.

It is the frequently recurring uncertainty about the safety and accessibility of this road that does the serious economic damage to Argyll.

54 dates of increased risk warnings out of a total to date of 181 days from 1st July to 28th December is 29.8%.

That is very far from being a negligibly negative statistic, with road users formally advised on each of these occasions – as they are today -  ‘to exercise extreme caution’.

This statistic is the unchallengeable case for a competent and permanent solution to the economic fragility this unable road bequeathes Argyll.

It is the case for the outright rejection of what is described by the report itself as no more than ‘a significant step change in the landslide hazard reduction for the A83.’

How the evidence is managed to achieve the desired solution

The evidence of the report itself has been modified and, in other instances, ignored, in order to support the selection of the recommended solution.

In the ‘more detailed economic appraisal’ which produced the recommended option – in the Table listing all three of the shortlisted three options against their ‘Performance of Options Against Appraisal Criteria’, the evidence is simply dishonestly distorted.

All three final options are scored equally for reducing the possibility of landslide debris reaching the toad and consequently for reducing the economic impact on Argyll of lost journeys.

Their equal scoring on this criterion is transparently dishonest since the debris netting option was the only one of the original six that could not earlier be described as reducing to ‘negligible’ the arrival of landslide debris on the road. At best it could only be described as ‘a significant step change’.

The detail of the timescale [15-35 years] of the beneficial impact of the proposed planting in the recommended option is tucked away in the body of the report and is not put forward as part of the upfront consideration of this option by Taskforce members.

Under ‘Environment’ the recommended option of more debris netting is given the best rating of the three finalists – described as ‘Neutral’, where the viaduct option is given ‘minor’ and the road on the opposite hillside ‘moderate’.

So the visual impact of littering this powerful hillside with a collection of baggy bottomed fishnet tights is  environmentally ‘neutral’?

Moreover, the report makes no consideration whatsoever of the environmental impact of more debris netting over the hillside on the golden eagles seen hunting there regularly, swooping on their prey. Is this impact also ‘neutral’? Where is the evidence?

Other failures in the report

What follows are the most centrally relevant of the failures of the Jacobs report.

  • Material inaccuracy: the incidence of landslide closures at the Rest

Under ‘Previous landslides’, the report declares: ‘In August 2004 Scotland experienced rainfall substantially in excess of the norm.  The rainfall was both intense and long lasting and as a result, a large number of landslides in the form of debris flows were experienced in the hills of Scotland. A small number of these intersected the strategic trunk road network including the A83. On this occasion, Rest and Be Thankful was not directly affected but landslides occurred at several locations between Glen Kinglas and Cairndow, the most significant being at Cairndow.’

This is factually incorrect. Rest and Be Thankful was indeed directly affected on this occasion in August 2004 and was itself impassable with a landslip at the point where conifers are grown on the uphill slope.

We also recall [and will check] that there was a single landslip at Rest and Be Thankful that preceded this one in 2004 at no significant distance in time – over 2003-2004 – causing road closure.

  • Material inaccuracy: incorrect ‘study area’

The report declares: ‘The area affected by closures of the A83 at Rest and Be Thankful includes Cowal, Mid Argyll, Kintyre, Islay, Jura and Colonsay.  This is referred to as the A83 study area.’

This is incorrect and, as such severely limits any competent evaluation of the economic impact of this unpredictable road..

Journeys from Glasgow to the Slate Isles, to Lorn, to Oban Airport and to Oban – with onward journeys to the isles of Kerrera, Mull, Lismore, Colonsay, Tiree, Coll and South Uist in the Western Isles are almost invariably made via the A83 from Tarbet – the most direct route.

The report’s inclusion of Colonsay in its chosen impact ‘study area’ also betrays careless ignorance. Colonsay may be one of the group of islands with Islay and Jura but it is accessed not from Kennacraig but from Oban, by water and air.

  • The mysterious economic study

The text mentions that an economic study on the impact of landslides on the A83 [to which the 'study area' relates] was carried out.

It does not say when or by whom this study was done; and it does not reference it to allow access to its method and findings.

We have shown a 2007 ‘Economic Impact Assessment’ carried out by Transport Scotland to be methodologically inept nonsense. How can anyone be sure that this limited and incompetent document is not still in currency here, to some degree?

  • Impenetrable and unevidenced Benefit Cost Ratio figures for each option

Under ‘Traffic and Economic Assessment’ the report’s description of the methodology by which these relative figures were produced is impenetrable. We are not ashamed to say we have no idea what this description adds up to and would be surprised if many others did.

Since the report gives no worked up example of how this methodology produced the BCR figures for any one option, there is absolutely nothing for an economist to use to test the validity of the process.

Treatment of Taskforce members

It is completely unacceptable to bounce members in the middle of a meeting with a fat report [padded with the usual practice of wholesale sweeping into it of unedited files from various bodies like the council, enterprise agencies, government departments...] and expect them to be able to say anything whatsoever about it.

This familiar practice deliberately reduces to patsies intelligent delegates who represent the Argyll  electorate, its business community and its travelling public.

This is a cynical abuse of good people, making it impossible for them to exercise their responsibilities and leaving them vulnerable to unfair accusations by those they represent of being asleep on the job.

The best solution

The best solution is clearly the viaduct option, which, at an estimated £83 – 95 million (at 2012 prices, excluding VAT), is more expensive than the chosen ‘significant step change’ option (£9-10 million at 2012 prices, excluding VAT) but is effectively the second cheapest of the six options considered, given its assured reduction to ‘negligible’ of the A83′s closure through landslides.

The viaduct option can be constructed parallel to the existing section of the A83 with less construction impact on the use of the existing road than the debris shelter option which would have to see it closed.

In terms of visual impact, the viaduct would have positive advantages, if it was well engineered with an eye to its aesthetic.

It could become a unique selling point of road access to Argyll – which would be a major transformation from the heavy economic drag of the current situation.

Argyll needs a decision to move on this option and an early date set for its construction.

Background material

Here are the Minutes of the Taskforce Meeting on 14th December at which thie Jacobs report was produced:

Here is the report itself again, for anyone who missed it first time around:

The report does concern itself, briefly, with the other problems suffered by the A83 and noted in the Argyll First petition, Sign for the A83:

  • the other section affected – seldom – by landslides, for which it acceptably recommends debris flow netting;
  • the ‘pinch points’ at Ardrishaig, the Erinnes, Tarbert… for which it suggests traffic lights.

At the A83 Taskforce meeting on 14th December, under question from Councillor John Semple of South Kintyre, Transport Minister Keith Brown said that he was ‘looking closely’ at the issue of trunking the A83 all the way to Campbeltown. Argyll expects positive action to follow that close look.

The photograph above shows progress by Scotland Transerv on the emergency diversion route on the old  military road below the A83, earlier in December. It is worth noting that the 1,200 tonne landslide in early August this year dumped debris on down the hill onto this lower track.

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10 Responses to A83: Evaluation of Jacobs’ study and recommendation

  1. An excellent and helpful report. What is particularly worrying is the fact that there are to be enormous delays on the Loch Lomond road in the near future (indeed have been already, for quite some time, due to frequent closures)- in effect, the west coast is cut off. In addition, large sums are to be spent on a Crianlarich by-pass which – however desirable – can hardly be a priority weighed against the road south of Inverarnan or the Rest and be Thankful.
    As an aside, use of R&BT is not almost invariable; it is extremely dangerous, not least because it is favoured by continental visitors with hire cars … after a picnic or rest, it being such a wide, open road with little traffic, they are prone to hurtle along on the wrong side of the road. I, for one, find the main road safer and just as fast, despite time spent on very cautious driving south of Inverarnan.

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    • ‘the main road’? – the A83 is a main road, and to suggest that it has ‘little traffic’ is just not true. And if you find the A82 north of Tarbet ‘just as fast’ as the A83, could it be you rather than the ‘continental visitors with hire cars’ who is ‘hurtling along’?
      It’s an exaggeration to suggest that the road over the Rest and be Thankful is ‘extremely dangerous’ – and my experience over the years is that the biggest hazard is not landslides, or foreign visitors on the wrong side of the road, but the considerable number of our fellow citizens who have no patience, couldn’t give a damn for anyone else, and drive like there’s no tomorrow.

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  2. Are Jacobs notable for their office crackpipe parties? They’ve included an option that costs half a billion pounds! I have to assume this is for comic relief because I can’t take it seriously.

    I’d also take issue with the costings, although there seems little point given the other flaws; I’ve been studying Norwegian tunnel construction, and their actual construction costs per kilometre of tunnel vary between $5m and $100m. The variation is caused by the size of the tunnel bore, if there are multiple tunnel bores and difficulties caused by poor geological conditions and insufficient surveying. What is special about scottish rock that it costs the UK between 4 and 120 times as much to build road tunnels? The Norwegians have bored double bore tunnels with 3 lanes in each for $100m per km through the most difficult rock in Norway, there is something wrong with these figures and it stinks.

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      • The entire issue of the pricing of UK public sector contracts urgently needs to be addressed – but which people would know enough to make sense of it who could be trusted not to have a vested interest in the featherbedding or to be beyond the influence of those who have?

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  3. Does anyone know the content of the contract with the land owner of the Old Military Road? Could it be that a deal has been already struck for it to be used in perpetuity, thus supporting the cheapest option? Perhaps this report is simply going through the motions after the outcome had already been decided.

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  4. Call me cynical, but the flashing warning lights – that you report to have been in action on no less than 29.8% of the days between 1st July and yesterday – seem to me to have two functions: as a warning to drivers of the potential hazard, and as an ‘arse covering’ exercise by the highway authorities to mitigate the risk of successful damages claims in the event of serious injury or loss of life.
    This might seem fanciful, but is no more than the similar gap between legality and morality in the area of tax dodging.

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  5. Couldn’t agree more with Robert Wakeman’s comment re “arse-covering” and the warning signs. It’s an “We telt ye” get-out!

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  6. Was this written by a representative of the task force?

    I have a few queries about what has been written, as I am not familiar with the region but have done some research regarding topic:

    • Inclusion of colonsay – To my understanding Colonsay does operate a ferry service to Oban AND Kennacraig (via Islay). I also don’t understand how the inclusion of Colonsay can be considered ‘careless ignorance’ where it (incorrectly?) says ‘it is accessed not from Kennacraig but from Oban, by water and air’ and mentioned that in the previous paragraph that the A83 is used as ‘the most direct route’ to Glasgow. To my understanding that implies that Oban should be considered within the study area, and should therefore be irrelevant wherther the Ferry from Colonsay goes to Kennacraig or Oban since both use the A83?
    • ‘The mysterious economic study’ – the study was carried out by Optimal Economics and is Appendix F. not so mysterious now I suppose?
    Apologise if these all seem naive, but I have a keen interest within this area and didn’t understand the bases for some of the arguments against the Jacobs reports.

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    • On Monday, Wednesday and Friday, the Colonsaty ferry service is a return from Oban.
      On Saturdays, the ferry starts from Port Askaig on Islay, comes in to Colonsay and terminates in Oban at 10.45. A return service then leaves Oban at 13.30, goes to Colonsay, on to Islay and terminates at Kennacraig.
      At no point is Colonsay served by ferry from Kennacraig.

      We argued in this piece that Oban should absolutely have been included in the area for Jacobs study of the impact of the closure of the A83 at Rest and Be Thankful. This is the route almost all Oban folk use and it is the route most users of ferries out of Oban take.

      The economic study failed to take account of the spectrum of common impacts on, for example, accommodation providers, when the Rest is closed.
      Thank you for the information on where to find the ‘economic study’ – which we will now scrutinise.

      Neither its authors nor its presence as an appendix were referenced where it was mentioned in the text of the report – the required practice, even in student work. There was therefore no reason to look for it in the appendices. That lack of reference is too is professionally careless.

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