Road engineer questions A87’s “flawed” speed limit reduction


A Highland road engineer has questioned the “flawed” proposal for a speed limit reduction on the A87, and the information it has been based on.

Transport Scotland have proposed that the speed limit on a 12-mile stretch of road on the A87, from Cluanie Inn to Kintail Lodge Hotel, be reduced from 60mph to 50mph. A critique of the proposals has now been prepared by consultant engineer Colin Mackenzie from Helmsdale, who has 30 years’ experience of designing roads in the Highlands, including the A87 on Skye, is a former roads and transport and trunk road manager for Sutherland, and now works in the private sector.

He told the Free Press: “In my assessment the whole process may be flawed. They should be looking for other ways to reduce accidents — a speed limit is a last resort — and it’s not clear that Transport Scotland have gone through that process.

“There are some statements in the speed review on the A87 that cause concern. I approached Transport Scotland three weeks ago regarding this and have had no reply. It is very unfair that during a limited period of consultation time you don’t have full information.”

The Transport Scotland review document admits that following the imposition of a reduced limit it is ‘unlikely that there will be a significant change in either accident rates or mean speeds’.

In his report Mr Mackenzie states: “The A87 through Glen Shiel is a key Highland road serving fragile rural communities in Skye, Lochalsh and the Western Isles. This is a road that might be considered by many as ‘good’, having been built to the modern standards of the day some 50 years ago. There is little or no frontage access, generally good visibility and light traffic of 2,000 vehicles per day. The 2008-10 accident rate was above the speed limit review threshold, but is a blanket 50mph limit the best way forward?

“The Transport Scotland review document admits that following the imposition of a reduced limit it is ‘unlikely that there will be a significant change in either accident rates or mean speeds’. It also makes it clear that the main aim of the review is ‘to achieve consistency on the network’.”

While the 2008-10 accident rate is 55 accidents per 100 million vehicle kilometres, Mr Mackenzie notes that if the 2011-13 Crashmap records are used the rate falls to about 21 accidents per 100 million vehicle km, which would justify keeping the present 60mph limit. The critique also questions the measurement of mean speed – found to be 49.8mph in the review – and whether “a singular spot mean speed can sensibly be applied to a 19km section of road that includes long straights and tight bends”.

Mr Mackenzie adds: “The value of 49.8mph used in the review does seem low when compared to the section from Cluanie to Bun Loyne (54.6mph) and other roads of similar character. Given that consistency across the network was a key reason for the review it is interesting to compare the Glen Shiel road (50mph proposed) and a selection of similar (or ‘worse’) roads where the 60mph limit is being retained. How is this consistent?”

The speed limit review states that alternative options should always be considered before a new speed limit is introduced, but Mr Mackenzie said it was unclear what other options had been considered for the Glen Shiel road. Mr Mackenzie commented: “Arising from the review, motorists from Skye and Lochalsh will be subject to no less than 63km (40 miles) of new 50mph restrictions on their journey to Glasgow, nearly a quarter of the total length.

Notices regarding the proposed speed restriction have been posted on stretches of the A87 with no lay-bys
Notices regarding the proposed speed restriction have been posted on stretches of the A87 with no lay-bys

“There are legitimate questions that can be asked about the application of the assessment process to this road. Why have communities not been better informed? Why have they not been involved in discussion on alternatives to a reduced limit? How was the speed measured and why is it less than similar roads? Why have other roads with higher accident records not been downgraded?”

He concludes: “A number of apparent errors have been found in the limited documentation available and this, together with the inconsistency mentioned above, inevitably raises questions about the reliability and scrutiny of the process. It is open to Scottish Ministers to suspend further implementation until these issues are clarified and resolved.”

Another former road engineer, John Hutchison of Lochaber, also called the plans “illogical”.

He said: “The idea is that speed limits suit the road and so drivers respect them, but a limit on a straight road seems illogical. There are a couple of bends on the road which are bad but this seems a draconian way to create uniformity when the country is not uniform. The section in question is too long and doesn’t suggest it needs this limit.”

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Dornie community council chair Shona MacLennan welcomed the critique by Mr Mackenzie

Shona MacLennan, chair of Dornie and District Community Council, launched a petition against the proposals which by the middle of this week had attracted over a thousand signatures. She welcomed Mr Mackenzie’s findings: “It’s very helpful to have confirmation that some of what we’d suspected about the review has been backed up by expert knowledge. What we’re looking for is that the current matter is suspended on the basis that the process of making recommendations seems to be flawed, and we would ask that the recommendations are reviewed before the statutory process is resumed.”

Originally set to close on Thursday 26th February, the consultation has been extended to Thursday 5th March, a Transport Scotland spokesperson confirmed this week.

See also: Campaign against A87 speed limit gathers pace