Heavy vehicle drivers in the Thames and Coromandel districts are being asked to avoid the "highly sensitive" SH25.
The New Zealand Transport Agency asks that drivers use the Tairua way around SH25 to minimise further damage to the road.
The highway is now open to north and southbound traffic, however travel on the western side is through an escorted convoy, and a number of work sites that are still under repair.
More work is required at multiple sites after the highway was damaged in last week's storm.
In total there is extensive damage to 29 locations along the 42km of highway between Thames and Mania.
Roadworks stretch for 2.4km in total, with some having been repaired and others still waiting for repairs before the road can open fully.
"We really do need heavy vehicles to continue to use the longer route because the Thames Coast Road is still highly sensitive to further damage.
"While the road is open to traffic long delays may occur so motorists are asked to defer their journey or take alternative routes if possible," NZTA transport system manager Karen Boyt said.
The transport agency expects the road to be open tomorrow, however some parts of the road will remain only open to one lane - they advise motorists to expect long delays.
"Over the last 72 hours the Transport Agency and our Contractor, Higgins, have worked very quickly to repair and make these sites safe," Boyt said.