Speed restrictions and temporary traffic signals are in place at both sites.
Seal widening work is being carried out on the northern side of the Mohaka Hill, the northern side of Devil's Elbow and near Whirinaki.
Motorists can expect minor delays and are asked to observe speed restrictions.
Contractors are also carrying out crack sealing repairs at various sites along SH2.
On SH2 south between Napier and Dannevirke "pre-winter maintenance" is under way at several places along the route, with temporary speed restrictions and stop/go signalling in place. Minor delays can be expected.
Crack sealing and drainage repair tasks are being carried out, along with barrier installation projects, at various sites along SH5 between Napier and Taupo; speed restrictions are in force.
Restrictions are also in place at sites between Wairoa and Frasertown on SH38 where tree felling around power lines is being carried out.
Replacement of the Mangahohi Bridge near Ohuka is continuing, with slight delays expected.