A90 at Brechin- why has there been so many repairs?
A90 at Brechin- why has there been so many repairs?
Author
Discussion

slf2012

Original Poster:

313 posts

171 months

Thursday 3rd October 2024
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I travel the A90 occasionally and am always frustrated at the quality of the road at the Brechin bypass.

Normally when road is dug up it’s to allow services to be installed or modified, but I can’t understand why this piece of road has had so much work done to it. It’s almost as if it’s been dug up and badly repaired every 10 mtrs or so.

Does anyone know the reason for this?

trevalvole

1,963 posts

58 months

Thursday 3rd October 2024
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Yes, it is bad. On the rare occasions I travel on it, if it is quiet then some people drive in the northbound outside lane as it is better than the inside lane, presumably due to fewer HGVs.

I have some recollection that the underlying road surface might be concrete laid in sections, perhaps that's part of the issue? And perhaps the repairs are at the joints between these sections? I also recall that the northbound carriageway is much worse than the southbound one - may be for historical reasons - I don't know if this section of the road was ever single carriageway?

Edited by trevalvole on Thursday 3rd October 18:48

dlks151

389 posts

73 months

Thursday 3rd October 2024
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This section is one of the few remaining sections of concrete pavements. The replacement of this would mean full carriageway reconstruction which due to the fact the slab extends over both running lanes would mean complete closure and the A90 going down to single lane Contraflow for a very considerable period of time.

Its currently a case of mend and make do until Transport Scotland can find some money I’d guess.

trevalvole

1,963 posts

58 months

Friday 4th October 2024
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Thinking about it a bit more, I have a vague recollection that the road was originally single carriageway and that the southbound carriageway was built to the east while traffic continued to use what is now the northbound carriageway. That would explain why the northbound carriageway is concrete and in much worse condition than the southbound one.

slf2012

Original Poster:

313 posts

171 months

Saturday 5th October 2024
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The concrete base would make sense right enough. They seem to have repaired a lot of the southbound carriageway a few years ago so hopefully the rest will follow as money becomes available.

Desiderata

2,738 posts

79 months

Saturday 5th October 2024
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It's very similar construction to how the M9 passing Stirling was originally, concrete slabs as "floating" foundations. It was fine for the first few years, then the slabs settled unevenly until the whole stretch became a giant rollercoaster. I'm not sure about the A90, but the M9 was laid over the flood plain for the river Forth, basically an enormous bog for thousands of years until it was drained for farmland relatively recently. I remember digging down over 7 metres at one point to find solid ground only to find the hole filling up with water as the tide came in further down river.
They rebuilt that section of the M9 one carriageway at a time using enormous quantities of shale as a foundation the second time.

rossybee

1,010 posts

282 months

Thursday 10th October 2024
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trevalvole said:
Thinking about it a bit more, I have a vague recollection that the road was originally single carriageway and that the southbound carriageway was built to the east while traffic continued to use what is now the northbound carriageway. That would explain why the northbound carriageway is concrete and in much worse condition than the southbound one.
I'm old enough to remember the Brechin section still being single carriageway - can't recall if it was the northbound section as would have been at least 30yrs ago!!!

Patrick Bateman

13,036 posts

199 months

Sunday 10th November 2024
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This is the longest poor stretch of tarmac I’ve ever experienced. I sit in the outside lane going north when it’s quiet enough, much better than the inside lane.

Patrick Bateman

13,036 posts

199 months

Why are there still 50mph limits here, apparently becoming permanent?

https://www.gov.scot/publications/foi-202600500041...

Travelling northbound it's been 2 lanes open for ages and I see no justification for it remaining 50mph.


trevalvole

1,963 posts

58 months

Saturday
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It doesn't specifically say why it is becoming permanent, but I suspect it is because "of minor changes in carriageway levels", quite possibly for the reasons that Desiderata mentions above.

Patrick Bateman

13,036 posts

199 months

Saturday
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If anyone knows the details of how that justifies a permanent 20mph limit reduction I'd love to hear it.

John D.

20,490 posts

234 months

Saturday
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Patrick Bateman said:
If anyone knows the details of how that justifies a permanent 20mph limit reduction I'd love to hear it.
Presumably because it's not flat enough / up to the standard of a 70 limit road.

Patrick Bateman

13,036 posts

199 months

Saturday
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Seems utterly bizarre having driven it at 70.