DRIVERS using the Saltash Tunnel are being urged to remain vigilant as major upgrade works continue, with a new lane control system now entering a critical testing phase.

The scheme marks a significant investment in tunnel safety, aiming to improve how traffic is managed and how quickly incidents can be responded to along one of Cornwall’s busiest routes. Engineers have now begun testing newly installed overhead lane signals, representing a key milestone in the project.

During this phase, motorists will notice unusual signal patterns displayed above the carriageway, including sequences of coloured dots in green, red and white. Despite their appearance, drivers are being strongly advised not to follow these signals while testing is underway. Instead, existing traffic management measures remain in place and must be followed at all times.

Electronic message boards are also being used to reinforce the instruction, displaying warnings such as “Testing overhead signals, stay in lane” to ensure drivers are clear on how to proceed. Testing is primarily being carried out overnight between 8pm and 6am, Monday to Friday, to minimise disruption during peak travel times.

The next phase of testing will see the system begin displaying familiar lane control symbols, including red crosses and green arrows. While these are the signals that will eventually guide traffic, drivers will still be required to ignore them until the system is fully operational. Officials say further updates will be provided ahead of this stage.

The tidal flow lane control system is expected to be switched on later this spring, once rigorous safety checks have been completed. The wider upgrade project is scheduled for full completion later in 2026.

Alongside the tunnel works, additional disruption is expected due to resurfacing on the A38 westbound carriageway between Manadon and St Budeaux. A series of overnight closures will be in place from 8pm to 6am on selected dates.

These include closures from Manadon to Weston Mill Junction on Tuesday, April 7, and Wednesday, April 8, followed by closures from Manadon to St Budeaux from Thursday, April 9, to Monday, April 13.

Further closures will take place from Manadon to Weston Mill Junction between Tuesday, April 14, and Thursday, April 16, and from Manadon to St Budeaux from Friday, April 17, to Friday, April 24.

In addition, an eastbound closure between St Budeaux and Manadon is scheduled for Monday, April 27, to allow survey work to be carried out.

Clearly signed diversion routes will be put in place throughout the works, directing traffic via the A38, A386 and Crownhill Road.

Drivers are being advised to plan ahead, allow extra time for journeys and check for the latest travel updates before setting out. Officials have warned that dates may change at short notice due to weather conditions or operational requirements, meaning some works could be extended if necessary.

Motorists are also reminded that closures and traffic management arrangements can change quickly, and are encouraged to stay up to date with the latest information to avoid unnecessary delays.