The Beaminster Tunnel is to finally re-open a year after the tragedy which claimed two lives.

Dorset County Council will open the road to two-way traffic at 10am on Monday, July 29.

Temporary traffic signals may be used to allow the contractors to finish off work and ensure the safety of road users.

However these signals will be used only at non-peak times and not during the weekend.

A landslip closed Beaminster Tunnel on the evening of Saturday July 7 last year, the day devastating floods hit West Dorset.

But it was only ten days later that the horrific truth emerged - the huge mudslide had crushed a car, killing its occupants Rosemary Snell and Michael Rolfe who were travelling home through the tunnel after having dinner in Beaminster.

The A3066 axis road from Bridport to south Somerset has been closed at the tunnel ever since as a result of fears that the surrounding land and potentially the tunnel structure are too unstable to guarantee its safety.

The 345 feet long Horn Hill tunnel north of Beaminster was completed in 1832 and is a grade two listed structure. It is 20 feet high and 20 yards wide and when built was hailed an exceptional civil engineering achievement for its time, allowing trade traffic to head northwards to Bristol through the hill which is 650 feet above sea level.

The closure of the tunnel this summer caused alarm among the Beaminster business community as shoppers and passing trade bypassed the town and prompted a publicity campaign to promote the fact that Beaminster is open for business as usual.

Rebecca Knox, local county councillor, said: “At last the news is good - the date that you have all been asking about for over a year now. This is great news for us all and particularly those who have been affected by the diversions – whether it was travelling them or living along the busy lanes that had to be used. It has been a frustrating year, but, now, we can get on as before, bearing in mind this was a terrible tragedy and our thoughts are with those family and friends of those who sadly died last year.

“We will finally know the road is open when those diversion signs disappear. What a welcome that will be for everyone.”

The A3066 was closed due to a large landslip at the North end of the tunnel, in which two people tragically lost their lives. The road has been closed since early July 2012 for extensive stabilisation work and rebuilding of the portals. The £2.1m project was initially delayed by complex land ownership issues and very bad weather, which prevented access due to the steepness of the slopes.

The current stretch of dry weather has meant that work has progressed as planned. All the soil nailing and mesh to retain the slopes has been completed and the head wall that was destroyed in last year’s land slip has been rebuilt. The walls at both ends have been protected with additional concrete walls constructed behind them. The walls on the approaches have been stabilised.

From now until the opening day the remaining work will be completed.

This includes:

• connecting the drains drilled deep into the hillside to the drains that go behind the retaining walls on the approaches

• removing the temporary ramps that provided access for work above the tunnel

• reinstating and testing the lighting on the approach and in the tunnel

• resurfacing the road on the approaches and within the tunnel.

Hilary Cox, Dorset County Council’s Cabinet member for environment, said: “This is fantastic news. It has been a very complex project and we have had to overcome a number of difficulties. It has been a test of our engineering skills to find long term solutions to make sure the land around the tunnel is stabilised for the safety of road users.

“The slopes will look strange initially, but we will sow wild flowers and then let nature do the rest.”