According to Star News, State Highway 1 between Christchurch and Dunedin reopened at 18h00 on Wednesday.
Road users can cross the Rangitata River via a bridge near Arundel on Route 72 but can expect delays due to speed restrictions and increased traffic volumes.
On the other side of the island, State Highway 6 between Franz Josef and Fox Glacier reopened on Wednesday morning, Star News reports.
Road users can expect a slow journey in places where crews continue to remove and remediate slips sites and road shoulder damage.
Following a slew of extreme weather conditions across New Zealand, the State Highway 1 over the Rangitata remains closed but it is likely to remain closed until at least Wednesday according to KiwiRail.
Work is being done to redirect and drain major stop bank breaches along State Highway 1.
It is understood at least 13 slips block the road at Mt Hercules, four of which are significant.
The New Zealand Police have declared the five nautical miles around White Island a no-fly zone following a volcanic eruption. They also urge the public to avoid the Whakatane Heads and Muriwai Drive areas.
On the west coast of New Zealand, more extreme weather conditions have caused road closures.
According to The Press, stormy weather that caused a landside has resulted in State Highway 6 on the West Coast to be closed. Press Association says road access to Franz Josef is not likely to be restored until Friday.
On the other side of the island, State Highway 72 near Arundel remains closed due to flooding as well as State Highway 1. The roads will be closed for the coming days, The New Zealand Police reports.