Tunnel's 'European-first' upgrade set to go live
National HighwaysAn upgrade to a road which carries 40,000 cars between Devon and Cornwall every day is the first of its kind in Europe, the company behind the work says.
The A38 Saltash Tunnel has been fitted with a new reversible tidal flow lane control system which allows operators to change the direction of one or more lanes to meet traffic demands.
National Highways said it began updating the 38-year-old structure in early 2025, with the system set to go live on Tuesday.
The government-owned company said the move was "essential to make the tunnel fit for now and for the future".
Over the past year, contractors have been working to install new signs and 31 miles (50km) of cabling.
The three-lane tunnel, which carries between 38,000 and 40,000 vehicles daily, would be able to manage traffic flow during the busiest times, National Highways said.
National HighwaysNational Highways added the new system would be operated in tandem with the Tamar Bridge control room.
"Our systems have been operating for 20-plus years, so it's essential that we make the tunnel fit for now and for the future," said National Highways' tunnel manager Julian Mitchell.
"We're now nearing the completion of this generational upgrade, one which has presented a significant challenge and involved a complex operation."
As part of the switch-on, the westbound 30mph speed restrictions from Carkeel roundabout would be removed and returned to 50mph, staff said.
