Median barriers would have prevented Sunday's deadly crash near Picton, according to road safety campaigner Clive Matthew-Wilson.
Matthew-Wilson, who's the editor of dogandlemon.com, told Breakfast successive governments have been is too focused on speed reduction as a way to reduce the road toll.
"They are fixated with speed, they are fixated with lowering the speed of cars when the people who cause speed-related accidents don't read speed signs."
"Asking people to drive safely is an expensive waste of time, 50 years of research shows that.
"So the solutions are all technological, if a median barrier had been on that road yesterday, there would've been no collision."
"The New Zealand roads are like a staircase without a hand rail, you make a mistake you're going to get hurt."
He said New Zealand doesn't need big highway projects to reduce the road toll and it's as simple as fixing up the roads the country already has.
"We need to move freight out of trucks and onto rail, where it's many, many times safer and we need to make sure whatever enforcement measures we're doing are effective and immediate," Matthew-Wilson said.
He said the Government has an old-fashioned approach when it comes to installing median barriers and too much money is spent elsewhere in the transport sector instead.
"The Government can find $55 million to plan a cycle lane across the Auckland Harbour but they can't find the money to install simple median barriers down the majority of our highways."
Matthew-Wilson said installing the barriers is an expensive exercise but compared to the cost of building new highways, it's "peanuts".
Prime Minister Jacinda Ardern told RNZ work was being done to bring down the road toll.
The Government had invested an additional $2.9 billion into road safety activities over the next three years, she said.
It had a target of a 40% reduction in serious road accidents by 2030.
In a statement on Monday afternoon, a Waka Kotahi spokesperson told 1News that a "technical engineering assessment of speed limits" along the section of State Highway 1, where the crash happened, had been undertaken earlier in 2022.
The findings of the assessment would "inform any future decisions on changes to speed limits for this section of SH1". It said it had already spent $2.5 million on the installation of side barriers on the state corridor between Picton and Blenheim between 2013 and 2018
The agency's spokesperson said there had been five fatalities and 21 serious injuries "along the 26km corridor of SH1 between Picton and Blenheim" recorded since 2012.
In the same time period, there had been one fatality and no serious injuries on the 1.5km stretch of road, around where Sunday's crash happened, between Freeths Rd and Lindens Rd,
The transport agency's director of land transport, Kane Patena, said his organisation would undertake its own investigation of the crash site to see whether any further safety improvements could be made.
"Waka Kotahi is continuing to assist the police serious crash unit, which is leading the investigation into yesterday’s crash," he said.
"We will also carry out our own review of the crash site, as we do in response to all fatal crashes on the state highway network, with a focus on the potential contribution of any road or roadside factors to the crash, and any safety improvements which can be made at the site."
"This crash will have a devastating impact on the victim’s families and throughout the wider communities of all those who have died or been injured. Our deepest sympathies are with them at this incredibly difficult time."