Those were part of the contraflow arrangement for the northbound Hexham Bridge, which was installed in 2003 when the southbound bridge was closed because a truck had collided with it [thanks Ozroads for the information]. It continued to be used for biannual night closures to service the southbound bridge but was removed as part of the Hexham Straight widening.
There's a cross-over facility on the Tomago side in order for southbound traffic to be pushed onto the northbound carriageway. At the set of lights in your GSV capture (#3900), traffic turned right toward Newcastle, then at another set of lights past Old Maitland Road (north)(#3899), traffic was able to U-turn back toward Maitland.
There was an AD [
GSV] facing the wrong way on the northbound bridge ramp which still had SR111 on it. In Vincent's GSV link there's a strange ID pointing Maitland and Sydney toward Newcastle, here's the angle it was meant to be viewed from:
GSV.