The Southern Motorway will be closed between Papakura and Drury from 7pm Saturday 21 May to 9am Sunday 22 May to demolish the Park Estate Road bridge.
Traffic will be detoured using Beach Road and Gt South Rd, with the road across the bridge closed to all but western end residents, who will be escorted across.
Underground service relocations and pavement work on either side of the bridge is nearing completion, as is the southern half of the new bridge.
The week before the demolition, the single lane through the construction site will be switched to the southern side and the new bridge, controlled by traffic lights, clearing the way for demolition.
During the work, the road surface below will be covered to protect it as rock-breakers break down the bridge, with the concrete and steel loaded to trucks for removal.
The rock-breakers are expected to start at about 8.30pm on Saturday and operate for up to six hours, with that period expected to be the noisiest part of the work.
There will also be night works in the week leading up to the demolition, mostly involving moving machinery, equipment and materials into the central median.
After the demolition, the remaining below ground piles will need to be broken out over another night, with that work still to be scheduled.
Contractors say the work will be noisy and generate vibration, but all efforts will be made to keep disruption to a minimum, with all work areas cordoned off.
For more on the SH1 Papakura to Drury project, visit nzta.govt.nz/p2b