"It is pleasing to know this work is now under way as research has shown just how effective these safety measures can be in reducing harm on our roads," Oldfield said.
The safety programmes would mean some disruption for motorists, he said.
Accordingly, NZTA would work in with the contract crews to keep both noise and traffic disruption down as much as possible.
"Traffic will be monitored and any delays kept to a minimum, however we advise people to plan ahead and allow a little extra time while work is under way."
The programme is an extensive one and the completion date has been set at mid to late next year.
A recent crash on the far northern stretch of SH2 has prompted urgent bridge repair work.
Temporary traffic lights have been put in place at the Tahaenui Bridge near Nuhaka north of Wairoa on SH2 where contractors have begun working.
The bridge was damaged about a fortnight ago when an army light armoured vehicle was in collision with a large van, which resulted in two people who had travelling in the van being airlifted to Gisborne Hospital with serious injuries.
In the wake of the crash the bridge was reduced to one lane while crash investigations were carried out.
While it had re-opened the New Zealand Transport Agency has again reduced it back to one lane for the repairs to guardrails to be carried out.
A spokesman said the work is expected to be wrapped up "in the next few weeks".
Along with the single lane temporary speed limits have been put in place along with the traffic light system.
Speed restrictions, along with stop-go signalling, are also in place on SH2 at Putorino where roadside drainage work is under way, between Bay View and Tutira for surface cleaning and Wairoa to Cricklewood for surface repairs.
On SH5 between Napier and Taupo roadmarking crews are at work between Eskdale and Tarawera while kerb replacement is taking place around the Titiokura Hill region.
