New date for three-month A458 road closure start

Work replacing the damaged culvert on the A458 at Spring Bank, Golfa will now start on Monday, January 24 it has been announced – meaning a three-month road closure.

After more than two years, it appeared that work would finally start last week, meaning the traffic lights would finally be removed, but Welsh Government’s Highways Agency said the project had been delayed for two weeks.

Diversion signs will be in place taking West and Eastbound traffic on a 15-mile route once work to replace the Spring Bank culvert starts.

Powys Councillors Graham Breeze (Welshpool Llanerchyddol) and Gareth Jones (Llanfair Caereinion) have been pressing the Highways Agency to get on with the work with a traffic light system being in place for over two years.

"It is hard for anyone to understand how long this work is going to take or indeed how long it has taken to get to this stage," said Cllr Breeze. "We will continue to press for progress reports to ensure this work is completed ahead of the Easter Bank Holiday."

The contractor for the project is GD Harries & Son Ltd.

What work is being done and why is it needed?

The work involves installing a new culvert beneath the carriageway to replace an existing culvert that has partially collapsed. The culvert is buried over at considerable depth beneath the carriageway, with the southern edge of the carriageway supported by a retaining wall

over 6m in height.

Major works are necessary to this retaining wall to install the new culvert whilst ensuring that the road remains capable of supporting traffic loads.

Why is the diversion route so long in comparison to the length of closure?

The diversion route is approximately 15 miles long and directs westbound drivers onto the A490 for 7 miles before turning left at the A495 junction to travel 8 miles along the A495 to re-join the A458, with eastbound drivers following the route in reverse.

The diversion route signposted is the shortest possible alternative route utilising similar or better classes of road (A roads in the case). This ensures that all vehicles – in particular HGVs – can negotiate the route safely.

Why can’t the work be done using traffic lights instead of a 24hr closure?

Due to the depth of the existing partially collapsed culvert and the narrow width of the carriageway, the full width of the road is needed to ensure the safety of the workforce and to eliminate the risk to road users.

During the works the full width of the carriageway will be excavated to the level of the culvert. Unfortunately, due to the constricted nature of the site it is not possible to carry out these works using traffic lights.

Why is it taking so long to complete the works?

The work involves over 350m3 of earthworks, the placement of over 50m3 of structural concrete, the craning of several new culvert units as well as fencing, resurfacing and other ancillary activities.

Every effort will be made to minimise disruption and reduce the length of time taken on site.

Why is the closure in place during the February half-term?

These works are essential to allow journeys to continue safely. The majority of the programme has been planned to take place during the winter months when traffic flows are significantly lower.

It is not possible to pause over the half-term due to the scale and complexity of the works; however, every effort has been made to ensure these works are completed by Easter.