Diversions And Disruption – Another Major Shaftesbury Area Road Closes On Monday

Dorset Council is closing Zig Zag Hill from next Monday, 20thMay, for 11 days. The B3081 will be shut along with another popular north-south route in the Shaftesbury area, the C13. That road through Melbury Abbas is likely to remain closed until 31stMay.

David Clegg from Dorset Council told ThisIsAlfred why this closure is required and he offered advanced notice of further local roadworks in 2019.

It has been a while since the road along Zig Zag Hill was resurfaced. “We’re probably looking at around 15 to 20 years ago when we resurfaced it last. On a road of that status is it what we would expect?” said David Clegg.

As Senior Site Agent for Dorset Council he manages some of the county’s road projects. “Over a two-week period, we’re going to be resurfacing the full length of the hill. This is primarily for safety concerns. The condition of the road is deteriorating on the bends. The corners are so tight. When lorries and HGVs are travelling up, as the vehicles turn on the corner, they have a habit of pulling the road surface with it,” said David.

Zig Zag Hill

David says the steep gradient of Zig Zag Hill presents some challenges. “We’re having to bring in some reasonably specialised equipment to help us deliver the scheme. So we’ve allowed nine working shifts to complete the work and we’re reasonably confident we should be able to hit that. We have resourced the job so that, if we are able to get ahead of ourselves and open the road before then, we will.”

David says the road must stay closed to the public throughout the works to keep the workforce safe and because it could be dangerous for drivers. “Because of the depth of reconstruction on Zig Zag Hill, it means that overnight, there will be rather large holes within the carriageway that wouldn’t be safe for a normal car to cross, so we’re having a 24-hour closure in place,” said David.

The work is only on the hill, so people living in adjacent properties will be allowed access. “We’ll have a hard closure across the carriageway and then we’ll have a man in a small van with flashing lights to provide residents with access and provide guidance to road users who are looking to get to particular points.”

Dorset Council say they decided to keep the C13 closed while resurfacing the B3081 Zig Zag Hill to avoid diverted traffic using the C13, rather than the signed route on the A350. The Highways Team is aware that closing two roads will put pressure on country lanes. They say once both schemes have been completed, an assessment will be made of any remedial work required on surrounding minor roads as a result of diverted traffic using them.

“History has shown us the when the C13 is closed, whether it is for roadworks or for accidents, road users do have a habit of following what we refer to as ‘informal diversions’, which ultimately lead to large amounts of traffic being pushed onto the rural network,” said David. “Our official diversion will be down to the A350. It’s an ‘A’ class road, which is designed for HGVs travelling up and down.”

David says the Highways Team did consider delaying the Zig Zag Hill work until the delayed C13 scheme in Melbury Abbas was completed. In that village, an electronic system that detects large vehicles is being installed. It will warn drivers of lorries to wait in a pull-in area when another large vehicle is approaching. That scheme, to address lorries becoming ‘stuck’ in the narrow village, commenced in January. It was expected to last three months, but it was recently extended until the end of May.

“This is primarily because of the ground conditions,” David explained. “We completed several trial holes throughout that section of the C13 just to establish what the road makeup is and what the geology is underneath the carriageway. Unfortunately, the results didn’t quite correlate with what we found when we started to dig the 1.5km long trench for the new traffic light signals, so it ultimately took a little bit longer to complete the trench.”

Works continue in Melbury Abbas

David is “optimistic” that the C13 road will reopen just after the May Bank Holiday. Dorset Council workers are also going to take the opportunity to make some repairs to White Pit Lane, while the road through Melbury Abbas is closed to non-local traffic.

“We’ve got teams completing drainage improvements along that stretch but also tackling those hard-to-reach bits of vegetation for clearance. So, where trees are overhanging the carriageway causing safety issues, we’re taking advantage of that closure.”

With two north-south routes closed for 11 days and over a Bank Holiday weekend, there is a concern if the A350 becomes blocked with an accident, there could be traffic chaos. David says the Council has a contingency plan. “We have alternate version plans in place that would divert traffic from Shaftesbury, along the A30 towards Henstridge and then dropping southeasterly down towards Durweston Bridge on the A357. The service that we offer is 24 hours, so we have a number of emergency supervisors and duty engineers who would manage events like that, out-of-hours, but it’s something which we are set up to respond to,” said David.

There are some other projects in David’s calendar that Shaftesbury area drivers might want to be aware of, including works on Durweston Bridge running into the summer. “On the A357, there are three large flood arches, which we’re widening and increasing the capacity of. The majority of that work will be completed with the road open. We will be working from the field underneath the carriageway. There will be times where we have to have three-way traffic lights there just to make sure the site is safe for vehicles to travel over.”

And David says an additional set of works will take place later in the year. “At the junction of the C13 and Boundary Lanes, near Compton Abbas Airfield. That junction is particularly dangerous to be pulling out onto the C13.” He says that junction will be realigned, “With the ambition of starting work before the end of the year.”

He hopes that a road closure won’t be required there. ” We’re working towards trying to deliver all that work using traffic signals to maintain traffic flows through the area. As you can appreciate, a lot of the residents in that vicinity are relatively tired at the works that have been carrying on and the disruption to their lives, so we’re doing everything we can to minimise that.”

To recap, there will be a full closure of the B3081, Zig Zag Hill, between 20th and 31st May. The C13 remains closed through Melbury Abbas until 31st May.