Waka Kotahi said the work was crucial to futureproofing this stretch of highway.
The agency advised motorists to plan for delays and follow traffic management and the lower speed limit which is in place.
Further north, in Ruapehu, SH4 between National Park and Tohunga Junction will be closed on select days due to road maintenance.
The highway is being renewed at the Makatote Viaduct and the size of the machinery needed means road users will be unable to fit alongside the machinery so this section of the highway will be closed in both directions from January 11-13, January 16-18 and January 22-23.
All of the closures will be from 8am to 4.30pm.
Southbound traffic on SH4 can detour left onto SH47 at National Park, right on to SH46 at Tongariro, right on to SH1 at Rangipo, right on to SH49 at Waiouru and back on to SH4 at Tohunga Junction.
Northbound traffic will detour in the opposite order.
The detour will add about one hour to motorists’ travel times.
Stop/go traffic management will also be on-site on other days between 6am and 6pm.
The work is weather-dependent and may be postponed at short notice.