Temporary speed restrictions have been put in place on SH5 around the Glengarry region while a tree-felling programme is carried out.
As well as reduced speeds, a stop-go signalling system will be in place at times.
There would be "occasional" delays for motorists using the highway through to Taupo, a New Zealand Transport Agency spokesman said.
Two highway works programmes on the stretch also have temporary speed restrictions in place.
Contractors are carrying out repair work on the Waione Bridge at Tarawera as well as road surface repair work also in the Tarawera region.