Buses will replace trains between Aberdeen and Dundee on Sunday, April 28, as engineers commission the first phase of signalling improvements on the line.
Work will be continuous from Saturday night to Monday morning as new LED signals and axle-counters are introduced.
Newtonhill signal box will be de-commissioned and control of the signalling section will be relocated to Aberdeen.
Network Rail say this will deliver increased capacity on the line ahead of the May timetable change and allow more trains to move through the area safely and more efficiently.
Part of a wider £13.5 million project between Aberdeen and Stonehaven to increase capacity, the work involved track and signalling improvements and the installation of a new track crossover at Craiginches.
Network Rail programme manager Jeremy Spence said: “These works will deliver the extra capacity needed to support further changes to local services between Aberdeen and Stonehaven as well as improvements to rail freight operations in the area – which benefits both passengers and business.
“Aberdeen’s rail network is seeing huge levels of investment that will help to create more opportunities for commuting and leisure travel and help grow the economy and put passengers and freight users first.”