A Looe councillor has shared confidential documentation to highlight the impact major improvements on the Saltash tunnel will have on the local area.
National Highways who manage the tunnel released the information in a communications activities plan to the Cornwall Gateway Community Area Partnership.
The plan was uploaded to a social media platform after the meeting earlier this month.
Cllr Armand Toms, who is the Cornwall councillor for Looe East and Deviock and member of Tamar Crossings Joint Committee, said: “The works on the Saltash Tunnel with have an impact of the day to day life of many residents of my area.
“From going to work, shopping and getting to our hospital will all be made more difficult with delays at peak times of up to 45 minutes; that is Highways England prediction.
“I know that these works need to be done and that they are important but it will come at a cost to the communities Plymouth serve and the industries that work in it.
“The other issue is if less cars use the bridge there will be less income and pressure on its finances and we need to consider if some compensation should be given to the bridge.
“Best of all would be to make the bridge free for the duration of the works.”
The works to improve the tunnel are a major project of modernisation which will continue for at least a year the plan states.
The Saltash tunnel is a key link between Plymouth and South-East Cornwall and with its 'reversible' lane, relies on specialised technology which is approaching the end of its life.
National Highways is carrying out an extensive programme of work to upgrade the system to ‘keep everyone using the tunnel safe, provide more reliable journeys and reduce the risk of unplanned closures’.
The Cornish Times is awaiting a final release of the timeline for the works but the plans released by Cllr Toms show the work estimated to start this November with the largest amount of disruption expected in 2025.
A spokesperson for Cornwall Council said: “This is a significant investment into a key transport route between Plymouth and south-east Cornwall.
“We have been working with National Highways and statutory undertakers to co-ordinate all planned roadworks in the area to reduce the impact on the surrounding road network and keep disruption to a minimum.
“We are also liaising with stakeholders including bus operators to identify additional measures to help reduce the impact and promote alternative forms of transport.”
Saltash Town Council reported at their September full council meeting that Anna Gelderd MP had approached the Department of Transport regarding their call to increase rail services. It was also reported that queues are expected to reach back to Notter Bridge just outside Saltash, at peak times.