RAIL passengers are facing travel disruption as work to repair the Whiteball Tunnel starts this week.
Passengers travelling south are being warned their journey could be extended by an hour.
David Crome, First Great Western's general manager for the west, said: “This £15 million Network Rail work is essential to prevent the aging structure from deteriorating further and to renew rail track.
“While we have done our best to minimise disruption, journeys, diverted via Honiton or retimed to ensure customers can arrive in good time, will take longer.”
Rail bosses say the work is essential to prevent the aging structure from deteriorating.
With the tunnel closed, Network Rail will carry out track renewal and expand the drainage system on the embankment as part of a wider plan to reduce flood risks.
Trains will be able to run to Taunton from London and Bristol, however usual train times for services will be altered and service frequency reduced.
A bus replacement service will be in operation between Taunton and Tiverton Parkway, Exeter St Davids and Tiverton and Exeter St Davids and Taunton.
For more information on how this work will affect rail journeys, call 08457-000125.
Are you going to be affected? Contact reporter Michael Marsh on 01823-365105, firstname.lastname@example.org or tweet @GazetteMMarsh