Train services between Norwich and Lowestoft have started running again after three weeks of engineering work.
The Wherry Line has re-opened with a fully modernised signalling system which has been switched over from the old Victorian mechanical semaphore method to a computer-controlled system.
It included upgrades to level crossings at Cantley, Strumpshaw and Oulton Broad North.
Additionally, passenger services have re-started on the line between Reedham and Great Yarmouth serving Berney Arms after an 18-month closure as part of the re-signalling programme.
"This major upgrade will provide huge benefits to those who travel on the line.
The Norwich to Great Yarmouth line reopened last week using the new signalling system together with a section of the East Suffolk line between Beccles and Lowestoft.
The return of passenger services to these lines completes a 23-day engineering works programme which began on at the start of February.
Ellie Burrows from Network Rail said: "The completion of works over the last 23 days is a significant achievement for everyone delivering the re-signalling and track renewals programme."
Work on Postwick bridge near Norwich was due to be part of the project but had to be postponed because of Storms Ciara and Dennis.