Work on the Auckland Harbour Bridge is going to plan -- following the successful installation of a permanent strut

All eight lanes of the bridge are expected to open by the end of the week.

Six lanes were closed overnight to allow space for cranes and cherrypickers to install the five-tonne, 22.7-metre strut.

The Transport Agency's Brett Gliddon says they will carry out surveys over the coming days to check there's no stress in other places.

He says that's to make sure the bridge is behaving in the right way, but they're confident no more work needs to be done.