Major changes to the Sydney Harbour Bridge have now come into effect with traffic delays expected.

Southbound motorists are being warned to allow extra travel time due to the reconfiguration of lanes, following the removal of the old toll plazas.

Those wanting to use the western distributor will now need to use lane 5 and 6, on the left.

Those wanting to reach City North via Grosvenor Street or York Street will need to use lane 4 and 5, on the right.

Changes to southbound lanes of the Sydney Harbour Bridge

Click PLAY below to hear Transport NSW Coordinator General Marg Prendergast explain the changes in full