Rest and Be Thankful: Landslide-prone A83’s emergency diversion route upgrade to start within weeks

The £30m Old Military Road scheme in Argyll is to prevent flooding and being hit by debris again

Upgrading the emergency diversion route for the landslide-prone A83 at the Rest and Be Thankful pass will start within weeks, Transport Scotland has told road industry chiefs.

The £30 million improvements to the parallel Old Military Road in Argyll, announced a year ago, will protect it from flooding and being engulfed by a landslip again after it was hit three years ago.

The road through Glen Croe will be widened from largely single track to mainly two-way, apart from at hairpin bends at the north end. Work will begin with the first of three phases, focusing on moving the southern end of the road from a flood zone.

The 20ft-high bund built to protect the Old Military Road after it was engulfed by a landslide in 2020. (Photo by John Devlin/The Scotsman)

The second phase will see landslide protection measures such as debris and rockfall fences, bunds and drain improvements. They follow a 600ft-long bund comprising giant sacks of gravel stacked 20ft high being built where a landslide engulfed the route in 2020.

Some bends will be widened, while two-way sections are extended in the third phase.

The so-called “medium-term solution” is also needed because it will be used by traffic during some phases of the construction of the “long-term solution” to the A83 landslide risk. That project, expected to start around 2027, will involve a debris shelter being built over the road for nearly a mile to protect vehicles.

Without the Old Military Road, diverted traffic on the main route between Glasgow and Kintyre would have to travel via Tyndrum to the north, adding more than an hour to some journeys.

More bunds are to protect the Old Military Road after a 20ft high one was built after a landslide in 2020. (Photo by John Devlin/The Scotsman)

Insight: A83 Rest and Be Thankful's last line of defence in Scotland's latest battle against climate change

Transport Scotland project manager Gordon Ramsay told the Road Expo Scotland event at the SEC in Glasgow: “This is a bold statement, because I am conscious of the date, but we are looking to start construction before the end of this year. I appreciate that’s quite tight, but we are pushing everything to progress this as quickly as we can.

"Thereafter, phases two and three will commence as quickly as we can, assuming we can get all the correct consents in place. If there is a significant landslide that closes the A83, we want the Old Military Road to stay open and avoid having to divert road users round the lengthy diversion.”

However, Mr Ramsay said making the entire Old Military Road two way was too costly and complex.

The Old Military Road diversion route, centre, runs parallel to the A83, left, at the Rest and Be .(Photo by John Devlin/The Scotsman)

He said: "The challenge is in the hairpin bends at the north. To make them two way would be a huge civil engineering construction and it’s very challenging with the lie of the land.”

John Gurr, chair of the the Rest and Be Thankful Campaign, said: “It is good that Transport Scotland is doing something, but the timing is not great as we are in landslide season, so hopefully the Old Military Road will be available for use if we get rain like we did in October.

“But if you compare the Scottish Government’s performance in providing a safe two-way road that stays open when it rains to what Argyll and Bute Council is doing after the A816 landslides in October, where it had to replace a bridge and will be opening a new two-way way road bypassing the landslide in just two months, it shows what can be done with some focus and local urgency.”

A Transport Scotland spokesperson said: “It is not expected that phase one of the works will impact on the availability of the Old Military Road should the A83 be closed.

"The constructability requirements, including any need for traffic management, for future phases of the medium-term improvements, are currently being considered.

“The planned medium term improvements will increase resilience of the temporary diversion route by reducing the likelihood of landslides impacting the route.

"These improvements will mean more certainty for locals and road users if the A83 has to shut due to adverse weather conditions.”