Works on a major rail programme between Aberdeen and Inverness will run 24 hours a day, seven days a week, for more than a month.
Residents in Aberdeen have received letters from Network Rail informing them of the project, which began on Monday and are not expected to conclude until August 20.
The line between Aberdeen and Dyce will be closed to allow engineers to double the track through the area and carry out bridge upgrades and signalling enhancements.
During the 14-week closure, hundreds of engineers will work thousands of hours laying 12 miles of rail over 20,000 sleepers and replacing or refurbishing five bridges on the line.
Once complete, the project will provide a day-time hourly commuter service between Inverness and Elgin by December and a half hourly service between Aberdeen and Inverurie by the end of 2019.
A Network Rail spokesman said: “The upgrading and double-tacking of sections of the line will allow us to run more services and improve the flexibility the railway can offer the expanding communities around Aberdeen.
“Our engineers will be working around-the-clock to complete this complex programme as quickly as possible. We understand the short-term inconvenience these works will cause to some residents and will minimise disruption as much as we can.”