Auckland councillors say the median barriers at a fatal car crash south of Auckland need to be scrutinised.
On Monday a truck travelling southbound on State Highway 1 near Ramarama blew a tyre, crashed through a barrier and hit a oncoming van carrying six people - along with two other cars, police said.
Three people were killed in the collision - all seasonal workers from Samoa - aged 45, 37 and 32.
Three others in the van were injured, and a 21-year-old remained in hospital in a critical condition.
Franklin ward councillor Andy Baker said he was concerned whether the wire barriers that separated north- and southbound vehicles were fit for purpose.
"It would be the right thing to do, I think, to investigate quite hard, whether they're the right thing in the right place."
Baker said he had travelled that section of SH1 for as long as it had existed, and it was used by many heavy vehicles.
"I'd just like to see the best barriers [in place that] we can, that will stop this sort of thing happening again, or make it as safe as possible," he said.
Manukau ward councillor Alf Filipaina said there needed to be accountability as police and the New Zealand Transport Agency / Waka Kotahi continued their investigations into the crash.
Earlier on Tuesday, Barry Geck told Morning Report the barrier was an older type.
"There are different types of barriers. The newer ones are definitely better at stopping trucks and vehicles and this one was more of an older type."
Geck said he had no concerns about the integrity of the wire rope barrier.
Waka Kotahi national maintenance and operations manager Andrew Clark said the agency was helping the police Serious Crash Unit, as well as conducting its own review of the crash site.
Although median barriers were routinely inspected, it would be looking at whether road or roadside factors had contributed to the crash, and any safety improvements that could be made.
Only concrete barrier would have prevented crash - experts
Meanwhile, Auckland University's Transportation Research Centre director Dr Douglas Wilson said it would have taken a concrete barrier to prevent the truck from crossing over the median.
Although wired rope barriers were tested for collisions at speeds up to 100km/hour, they were not designed to deflect all types of vehicles.
Improving barriers on our roads and highways was a gradual process, and New Zealand would need to consider what it could afford, Wilson said.
"We can't afford in our New Zealand system to put concrete TL6 (test level 6) barriers along all of our motorways and freeways to prevent those types of crashes.
"So we have to balance the cost of these things. It's not an easy thing for New Zealand Transport Agency to make these decisions.
"We can't afford the same systems as some of the countries we'd like to compare ourselves to."
Lower speeds mean lower risk of serious crashes - Green MP
Green MP and former Minister of Transport Julie Anne Genter told Checkpoint the crash was "horrific".
"It is something that no one in New Zealand wants to happen - to them or their loved ones - and that's why a focus on road safety and making our transport system as safe as possible is so important and should have cross-party support."
It was important to be "open to the evidence" of what was effective in reducing crashes, she said.
"An accident like this, that's nobody's fault - it's a failure of the vehicle - it can happen anywhere on our roads and so we need to spread the money across as much of our roading network as possible, to make it as safe as possible."
This meant more median barriers and passing lanes, as opposed to "very expensive new alignments, [or] four-lane expressways" - the focus of the current government, she said.
"Because that is so much more expensive, it necessarily means a much smaller proportion of our network is being made safe."
Higher speeds were more likely to result in deaths and serious injuries, and the government's approach to speed management had been widely criticised by road safety experts and trauma surgeons, she said.
Concrete barriers did not reduce the risk of fatalities to zero, and were much more expensive. With modern wire barriers you could ensure more roads were protected, given the transport budget, she said.
On an undivided two-lane highway - which was common in rural New Zealand - the safe speed could not be above 80kmh.
"That's just the reality. You will have a much higher risk of deaths and serious injuries at 100kmh than you do at 80kmh."
The previous government's Road to Zero plan had been to match speed management to investment in roads, she said.
The safety programme aimed to reduce annual deaths and serious injuries in road crashes by 40 percent by 2030, and eventually bring that figure down to zero.
The scheme included installing hundreds of kilometres of median barriers.
But in February the coalition government announced it was scrapping the programme.
"New Zealand can and should aspire to have a much safer transport system.
"When we look at countries similar to us, they have a much lower death rate per population and per kilometre driven... but we have to follow the evidence on that.
"This sort of thing is going to become more frequent, unfortunately, if the current government doesn't change its approach."