Vehicles will be unable to access the bridge from 8pm on Saturday night to 6am the next morning. From then on, traffic management will allow only Southbound traffic to cross the bridge.
The City of Edinburgh council have asked drivers to plan their routes to avoid the Northbridge where possible until both Northbound and Southbound lanes are open again.
Pedestrians will have access to the bridge via the eastern footpath, which will be re-opened, however, the western footpath will be closed.
The road has been closed due to refurbishment works. The council have said that, due to the nature of the works needed, there was no viable alternative to closing the bridge.
The implementation of this new traffic management phase will allow workers to complete the remaining 60% of refurbishment needed on the bridge.