Roads around the central bays of Auckland are closed for the almost 30,000 people taking part in the annual Round the Bays event.
Runners and walkers set off from the Quay Street starting point, and are following Tamaki Drive to St Heliers, as part of an 8.4 kilometre route.
Organisers said the first roads could be open from 10.15am, with all roads expected open by 12.30pm.
They said almost $250,000 was expected be raised for the Mental Health Foundation through the event.