Warning signs are being installed to slow motorists travelling on State Highway 1 at 100km/h to just 60km/h at two dangerous Northland intersections.
Work began this week on installing the signs to alert motorists travelling too fast where Mangapai Rd intersects with SH1 at Oakleigh and where Shoemaker Rd crosses the highway at Waipu.
Officials say the signs will improve safety at the intersections and by reducing the speed of cars on the highway, will make previously high-risk manoeuvres safer and easier for turning vehicles.
The same system of speed signs was installed on SH1 at the intersection with SH12.
The work on the latest intersections began this week and following testing they are likely to be in use for the summer holiday rush.
Signs display a 60km/h speed when sensors detect a vehicle approaching the intersection with the main road.
The signs on SH1 are about 150m from the side road and the sensors are also 150m from the highway.
The lower speed is displayed to warn drivers on the state highway or main road to slow down to reduce the risk of collision.
It is compulsory for traffic on SH1 to travel at 60km/h when the signs are illuminated.
NZ Transport Agency acting director of safety and environment Lisa Rossiter said the intersection speed zones were a simple, relatively quick safety improvement which have proven effective in New Zealand and overseas.
"These intersections are at locations that have a high risk of serious crashes involving turning traffic. by slowing the oncoming traffic the intersection speed zones will help prevent these crashes and reduce the risk of someone being killed or seriously injured if a crash does happen," Rossiter said.
The work was part of the government's $22.5 million national Boost Safety Programme which included a range of low-cost safety improvements such as rumble strips and better signage, to make 30 regional state highways safer.
The Whangarei District Council supported the proposal at this site. Police were also supportive and noted the system had been proved to contribute to a reduction of crashes at high-risk intersections.