One lane of State Highway 35 between Tolaga Bay and Tokomaru Bay on the East Coast will be re-opened to all vehicles on Wednesday.
The Transport Agency closed the highway four weeks ago after heavy rain caused a large slip to undermine the road.
Acting state highways manager Mark Owen says contractors and geo-technical engineers have worked tirelessly since then to make the road safe for all types of traffic.
Mr Owen says one lane was opened on Monday to light vehicles, but now trucks will be able to use it as well.
If the the condition of the road deteriorates, heavy vehicles will be diverted to the alternative inland road, he says.