Karangahake Gorge will be closed for two hours tonight as a truck's trailer unit is cleared from down a bank following a crash earlier this week.
A vehicle left the road between Waikino and Karangahake early Friday morning and fell eight to 10 metres into the river.
The truck was removed on Friday and the trailer's contents were removed on Saturday, but a crane will be used to pull out the trailer unit while the road is closed from 8pm-11pm.
Waikato Transport systems manager Karen Boyt said the removal has been scheduled when there are fewer cars on the road to minimise disruption to road users as much as possible.
"People should delay their travel if they can or use an alternative route between 8pm and 11pm tonight while the trailer is removed," she said.
Road users can get information by checking www.nzta.govt.nz/traffic, calling 0800 444 449 or following the Transport Agency on Facebook or Twitter.