Campaigners have registered their concern as Scotland's most notorious road is to shut down for the third time in 16 days as a "safety precaution" due to a forecast of heavy rain.

It has been confirmed that the landslip-prone A83 at the Rest and be Thankful will shut from 7pm on Saturday due to a forecast of persistent heavy rain.

Motorists are being now being told that official single track diversion route, the Old Military Road which runs through the centre of Glen Croe will act as a diversion using a convoy system.

A safety inspection will take place on Sunday morning to assess if it is safe to resume convoy operation on the A83 during the daytime.

Bear Scotland, the road maintenance firm contracted by the Scottish Government's Transport Scotland agency said that teams are monitoring the weather and any changes in hillside condition on a daily basis to inform operational decision making, with the wet weather forecast to continue into next week.

It is the third time the road has had to be closed in a fortnight, and campaigners have been demanding action over why the road is still not fixed.

It was shut over night on Tuesday as a safety precaution after a further closure on October 7 due to concerns over heavy rain.

The Herald:

Campaigners are continuing to urge transport minister Graeme Dey to take urgent action to prevent the continual closures.

Representatives of the Rest and Be Thankful Campaign are disgusted by the latest disruption coming amidst continuing criticism over money "wasted" over £8.5m of failed temporary fixes involving catch pits designed to ‘capture’ debris material from a landslip and prevent it from reaching the road.

Transport minister Graeme Dey has said that improving the resilience of the A83 at the Rest and Be Thankful "is one of our top priorities" and that they were continuing to work on a permanent long term solution to the issue. Eddie Ross, Bear's north west representative said: “The weather forecast for the weekend indicates that persistent heavy rainfall will occur from late on Saturday afternoon until Sunday morning.

“Saturation levels on the hill will increase with the forecast rain, and we have taken the proactive decision with Transport Scotland to close the A83 at the Rest and Be Thankful on Saturday as part of our safety first approach, with all traffic diverted via the Old Military Road through the glen.

“We will conduct a safety inspection on Sunday morning to assess if it is safe for us to reopen the A83 for road users, and we will have teams constantly monitoring the hillside and weather conditions in the area such that the route remains safe for road users.

“As ever we’re doing everything we can to manage the ongoing situation at the Rest.”

The Herald revealed last month that transport chiefs had spent some £8.5m on "wasted" temporary sticking plaster fixes to try to prevent landslips on the key road over five years.

Rest and Be Thankful Campaign chairman John Gurr said: "We are challenging why Transport Scotland are building more catch pits. It is not common sense to keep digging holes in the ground, we think it is just folly.

"We would argue that traffic needs to be routed away from the danger of major landslides urgently, not forced to navigate next to a catch pit that may or may not work.

"Other countries with similar terrain manage to deliver fast and safe infrastructure, so if this is 'one of the biggest engineering challenges in Scotland' do we have the right people with the right level of experience to deliver a project of this scale quickly." Construction of the last catch-pit on the road was completed in August having taken over twice as long to install as promised.

A new catch pit planned next to the trunk road, will be located at the foot of the steep sided channel formed by the major landslides in August and September last year.

Moves over the latest measures to prevent road closures came after a major landslip around 650 feet above the carriageway shut the road in August, last year.

Engineers said thousands of tonnes of debris including car-sized boulders slid onto the road after 100mm of rain hit the Argyll hills.

One of the landslip mitigation catch-pits, built to prevent landslip material reaching the road, caught around 2,000 tonnes - but it did not stop thousands more tonnes hitting the road.

The slip ushered in a series of road closures for the important Highlands route which by January had meant it was open for barely three weeks in the space of five months.

In February the A83 and the official single track diversion route, the Old Military Road which runs through the centre of Glen Croe was shut after hundreds of tons of debris fell in another landslip.

That is despite £1m being spent on 175-metre long, 6.6 metre high barrier having been built next to the OMR to stop debris from a potential landslip.

A campaign - backed by 1500 businesses fought for a permanent solution by 2024 after an over 15-year failure to prevent disruption.

A new A83 route which could include a tunnel close to the A83 has been identified as the Scottish Government's favoured permanent solution - but it is a long-term solution which could take seven to ten years to complete after being approved.

There are five new options on the table for the new Glen Croe route, some of which include tunnels up to 1.8 miles long.