Work on the next phase of the Clickimin footpaths will begin tomorrow, leading to the closure of the path on the east side of Clickimin Loch.
Footpaths on the west side of the loch via Westerloch Drive, are nearly complete and the paths will be open early next week.
But work will move to the path running beside the south football pitches, and the footpath will be closed from Monday morning until 30th June, or earlier if work is finished.
The footpath around the Clickimin rugby pitch will be closed until the new roundabout, tied in with the new Anderson High School, is finished towards the end of the year.
Shetland Islands Council said all paths are being resurfaced with tarmac and widened to three metres ahead of the new school being built.
The upgrades are being made through a grant of £507,500 from national transport organisation SusTrans Scotland, to encourage walking and cycling to school by pupils.
Pedestrians and cyclists will have an alternative route either along the newly upgraded path on the west side of the loch, via Westerloch Drive; or on the main road and pavements on South Lochside.
The route over Staney Hill between Clickimin and Ladies Drive will remain open for the time being.