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For modern road safety advocates, this is precisely the problem. Human error certainly caused the crash but rumble strips at the side of the road would have alerted Houseman that he was sliding into the gravel much earlier. If the van had been fitted with a modern Electronic Stability Control (ESC) system — which allows a driver to regain control after over-correcting — it would have been far less likely to flip and kill three people.
First impressions from the last few weeks could be that this kind of mayhem on the roads is still a regular occurrence, thanks to two high-profile crashes caused by foreign drivers which killed four people over Queen's Birthday weekend. Dutch businessman Johannes Appelman, 52, admitted running a stop sign and causing a crash that claimed the lives of schoolgirls Abigail Hone, 12, and Ella Summerfield, 12, and Ella's mother Sally, 49; American tourist Cody Dickey, 23, was fined $5,500 and disqualified from driving for 18 months for causing the death of Auckland grandmother Robyn Derrick, 52, in a crash on the Coromandel Peninsula.
But, in fact, such crashes are becoming rarer and the road toll is hitting record lows. Deaths on the open road have fallen from more than 250 a year in 2000 to just over 100 last year. The annual road toll fell to 254 last year, the lowest level since 1950. For the past few years it has been dropping faster than over-cautious analysts can predict, accelerating a trend that began in 1990. In 2011 the road toll dropped by almost a quarter (from 375 to 284 deaths), prompting a series of Ministry of Transport investigations into what was going right.
Researchers picked out rising petrol prices and decreased motorcycle registrations as having some effect on the spectacular 2011 drop but admitted they could not explain more than half the improvement.
The bigger question was why the road toll had been falling since 1990. At its peak in the late 1980s about 750 people were dying on the roads each year more than two a day but since then it has dropped by two thirds and appears to be still falling.
Infometrics chief economist Dr Adolf Stroombergen concluded last year that the real rate of improvement was even more spectacular, considering the greater number of people and cars now on the road.
His report said the death rate per kilometres travelled had dropped by 75 per cent, which was just as well. At 1990 rates, we would have had an annual death toll of 1,177 and an extra 12,300 people killed by 2012.
Stroombergen's report — thought to be the first to analyse the combined role of vehicles, roads and drivers on the road toll — concluded that more than 80 per cent of the fall could be explained by long-term trends. Of this, 45 per cent was due to safer cars and fewer motorcycles, 19 per cent was due to better roads and only 36 per cent was due to the driver behaviour factors, such as road safety advertising, breath testing and lower speed, which had received so much political attention for decades.
The effect of road safety advertising and police speeding and alcohol blitzes was difficult to quantify, according to Stroombergen, but one figure was clear. According to a Monash University crashworthiness study, a driver in a modern car was only half as likely to be killed or seriously injured in a crash as a driver who crashed in a vehicle built in the early 1980s.
Around the time of the Turangi triple fatal, the "ghost chips" road safety ad had already reached cult status in schools. Its best-known catchphrase — "I've been internalising a complicated situation in my head" — became a running gag, even though it dramatised the deadly serious dilemma of a young Maori man debating how to tell his friend not to drive home drunk.
But according to outspoken road safety campaigner Clive Matthew-Wilson, author of the Dog and Lemon Guide for car-buyers, ads like this don't work, no matter how good they are. "It's like telling teenagers the dangers of drug-taking. It sounds like it makes perfect sense but almost every study has shown that it doesn't work."
Matthew-Wilson claims the Government's road safety strategy is based on the false assumption that you can change driver behaviour. In fact, he says, most crashes are caused by five at risk groups — the very young, very old, very poor, very tired and very impaired (by drugs and alcohol) — who all think their driving is fine.
His view gets some support from the Infometrics study, which found roadside breath testing had only a marginal effect and suggested that while it might lower drink driving in cities, most deaths occurred on the open road.
The study added that the campaign seemed more likely to reduce road deaths by affecting driver behaviour in the long term but Matthew-Wilson thinks this is irrelevant.
"Police campaigns have been very successful in persuading the average New Zealander not to get behind the wheel after having a few drinks, but they're not the ones that generally cause fatalities. The fatalities are caused by young working-class males on the edge of the criminal community who don't see the slightest problem in their behaviour. In fact, they take pride in it."
Matthew-Wilson says the same problem applies to the speeding campaign, as 80 per cent of the road toll occurs below the speed limit. The killers, he says, are the extreme speedsters who ignore road safety messages, not your law-abiding middle-class drivers who tend to get caught on holiday weekends.
He regards the solution as simple: safer cars, safer roads with more median barriers and rumble strips and better public transport to keep at-risk drivers away from the wheel.
Automobile Association motoring affairs manager Mike Noon agrees the old approach of blaming and catching drivers wasn't helpful.
He thinks the Government could win a lot more public support for lower speed tolerance and speed cameras in general if at least part of the money went back into road safety, as it does in Australia.
But he believes police and transport officials are right to concentrate on lowering speed and drink driving and says we are already seeing the effects. Drink-driving convictions have fallen by a quarter from 31,058 in 2009 to 23,362 in 2012. In 1996 more than half of all drivers were snapped travelling above the 100km/h speed limit on the open road. Now only a quarter do so. The the top 15 per cent of all speeders were travelling at more than 115km/h in 1996. Now the cut-off mark is 102km/h.
Speed matters, says Noon, because it's a collective risk that builds across the thousands of cars on the road at once. "You're not greatly increasing your risk as an individual but if everybody does that, then across the network it does make a difference."
Noon also thinks the official line has already changed with the development of Safer Journeys, an award-winning road safety programme involving several Government departments and the AA, which attacks the problem from four angles — roads and roadsides, vehicles, speeds and road use. It has taken a while but safer cars and roads are now firmly on the political agenda.
According to the Infometrics study, safer vehicles accounted for 45 per cent of the falling road toll for two main reasons.
One was halving the death and serious injury risk through safer cars, the other was a big drop in young men riding motorbikes. Both stemmed from a flood of cheap used Japanese imports, which began in the late 1980s and initially improved safety. But the country's dependence on cheap older cars ever since has delayed the uptake of basic measures common in other countries, such as better airbag protection through frontal impact standards. Our cars are 13 years old on average, so safety improvements take a long time to trickle through.
That's why Noon is hugely enthusiastic about the introduction of Electronic Stability Control, which will become compulsory on all new cars next year, SUVs and off-roaders in 2016, large cars in 2018 and all vehicles by 2020.
"That's about as important as seatbelts. In 15 years that's going to have an absolutely profound effect on our road toll. It actually reduces single vehicle crashes by about 30 per cent and for SUVs (which are not as stable) by 60 per cent."
Transport Agency road safety director Ernst Zollner agrees, particularly after experiencing the technology himself in Australia.
"They put me in a car in the middle of nowhere and said, 'Now, try to drive into something.' I said: 'You can't be serious.' They said, 'Go on, try.' If you try to cross the median barrier, this car will not let you. It doesn't allow you to drive off the roads."
Both Noon and Zollner think the Infometrics study may underestimate the effect of road improvements. Zollner says road building stalled badly in the 1990s but recovered about 10 years ago, thanks to more money and a road assessment programme called KiwiRAP, which rates the country's roads to decide where safety work is needed.
Under KiwiRAP, roads have a star rating from one (worst) to five (best). They are assessed both on personal risk to one driver at any time and collective risk, which measures the total crash rate. Road safety improvements have concentrated on high collective risk zones, such as SH1 between Auckland and Hamilton. For instance, turning the winding one-lane section from Meremere to Rangiriri into a straight two-lane expressway with median barriers has almost eliminated serious crashes.
From 2000 to 2006, there were 22 serious crashes, nine of them fatal. In 2007-2011, there were three crashes, including one fatal.
Overall the number of serious and fatal crashes on the high collective risk sections of state highways dropped by 30 per cent from 2000-2006 to 2007-2011, suggesting that the improvements were working. As a result, the number of sections assessed as high-risk fell from 30 from just 11.
Zollner says it's hard to prove as conclusively that road safety campaigns to change drivers' behaviour are effective, because the answers lie inside people's heads. But his gut instinct is that they are, especially when education is backed up with enforcement. He says drivers are already adjusting their drinking behaviour in preparation for the reduction in the blood alcohol level from 80mg to 50mg per 100ml of blood at the end of the year.
"One cop told me it's becoming really hard to catch drink-drivers."
As for the ghost chips ad, there has been an encouraging improvement among young drivers, including a one-third reduction in crashes among all learn
This could be a pointer to long-term attitude changes or just a short-term effect from several other recent measures, such as raising the driving age, tougher practical licence tests and a zero alcohol limit for drivers under 20.
Zollner says he can at least be sure that the message is still alive and well in teen culture.
"We hear from the young co-ordinators in schools that it's now a standard joke at a party — but it's actually serious. They nearly play out the ads. Some academic at a university will have to sit down and make sense of it all, but they all know the ad."
• Read also: Drivers face lower speed on open road
