Multi-million pound work to repair and waterproof the Oldbury viaduct is set to get under way in the next few weeks.

The improvement scheme, which is valued at more than £100 million, is expected to finish in Autumn 2018 but some minor work will continue into Spring 2019.

To keep the M5 open during the work, a contraflow system is being put in place between junctions 1 and 2. From the end of July all traffic will be diverted onto the northbound carriageway, with two lanes operating in each direction, along with a 30mph speed limit.

Highways England said slip roads will be kept open throughout the work to ease the effects on the local network, but drivers are advised to expect long delays.

Motorists travelling from across the country are also being urged to consider routes, such as the M42 and M6, to keep congestion to a minimum on the M5 and surrounding roads.

Highways England senior project manager, Zbigniew Twarowski, said: “This is essential work although we appreciate it will also be frustrating for both motorists and residents.

“We’re doing everything possible to plan and manage the roadworks in order to keep traffic moving, minimise disruption and maximise safety.

This is how the M5 contraflow system will operate during the Oldbury viaduct improvement work.

“Drivers are urged to plan journeys in advance, allow extra time and consider alternative modes of transport, car sharing or working from home where possible.”

During the work there will be a 50mph speed limit on approach to the 30mph speed restriction between junctions 1 and 2, while digital travel information signs – linked direct to the regional control centres that monitor traffic flows – will provide real time advice including travel times and distances.

For more information about the work at Oldbury viaduct visit highways.gov.uk/oldburyviaduct.