Fatal Impact

The Bulletin

Wednesday 28 January 2004

Last week's horror smash on the Hume Highway has focused attention on the appalling safety record of 4WDs. Patrick Carlyon and Joshua Gliddon report.

Insecure? Vain? Self-centred? Self-absorbed? Lack confidence in your driving skills? Nervous about your marriage? If so, you are the stereotypical 4WD driver. These are the findings of internal car industry research reported in US journalist Keith Bradsher's controversial book, High and Mighty. Among Bradsher's other main points? Four-wheel drives aren't very safe. And many Australians who don't drive 4WDs, no doubt, will agree.

International studies abound suggesting that 4WDs are more dangerous than passenger cars, yet we keep buying more and more of them. Last year, about 150,000 new 4WDs were sold in Australia, compared with 588,000 passenger cars. Commercials depicting muscle-bound 4WDs storming across desert sands, or an executive riding a horse down the street, or the family barbecue next to the billabong, apparently work.

No matter that only about one in 10 4WDs bought in Australia get off the bitumen, that the big engine and clunky body designed for cross-country toil mostly prowls the suburbs. Nor does it appear to matter that 4WDs tend to roll over more often than passenger cars. Perceptions are different to statistics. People continue to buy 4WDs because they feel safer, and in this market, as with the marketing, perception is everything.

Yet common sense dictates that the taller the vehicle, the higher its centre of gravity. Rollovers of sports utility vehicles (as the Americans call 4WDs) and utilities made up about a quarter of the deaths on US roads in 2001-02, according to official US figures from the National Highway Traffic Safety Administration. Figures from a 2002 Australian Transport Safety Bureau study showed that 35% of all 4WD fatal crashes involved a rollover, compared with 13% for passenger cars. Last week, while travelling on the Hume Highway near Tarcutta, southern NSW, four members of the Allen family mum, dad and two of the four kids of Canberra, died when their 4WD rolled over on a tight bend

These accidents aren't mysteries. According to Stuart Newstead, a senior research fellow at Monash University's Accident Research Centre, 4WDs are about twice as likely to be involved in single vehicle crashes. He also dispels the myth that 4WDs are safer for occupants than cars, saying they provide no greater passenger protection than a large sedan. Even worse, they're extremely "aggressive" towards other cars in an accident, and up to 60% more likely to cause significant injury to passengers in other vehicles than conventional passenger cars. "That won't bother some people," says Newstead, "but if you've got any community conscience at all, the aggressivity should bother you."

So why are 4WDs more inclined to turn turtle than regular passenger cars? Automotive industry consultant Michael Paine has spent the past seven years involved in the Australian New Car Assessment Program (ANCAP), which independently tests the crashworthiness of popular vehicles. Paine says that 4WD rollover comes down to basic physics. They're taller, often riding on a narrower track (that's the distance between the wheels left to right). Put another way, they're more tippy-toed. Four-wheel drives are also less responsive than a normal car, he says, and don't provide as much driver feedback.

Paine paints a rollover as the product of a lot of variables coming together. Taken on their own, nothing might happen, but added up ... it could be deadly. "Say the 4WD drops its left tyre off the tar onto the unmade shoulder, the driver panics and over-corrects. The vehicle turns too quickly, comes back on the tar and starts to roll." The 4WD isn't rolling in isolation. It's the poor-quality road, the driver's poor reaction and the high centre of gravity all working together.

In the absence of perfect, or even good roads, and with Australia's relative indifference to driver training, the answer to saving lives rests largely with the vehicle itself. Yet many 4WDs don't meet passenger car safety standards. Nor do they have to. Take offset frontal impact occupant protection, when only part of the front of the vehicle hits an object, says Jack Haley, vehicle policy adviser at the NRMA. The new standard applies only to passenger cars. Haley says phased introductions of new rules has meant that commercial vehicles have lagged on structural design, thus have not had to meet the same level of severity in crash test performance.

Haley also points to the differing heights of energy absorption structures in 4WDs and passenger cars. The structures are designed to feed crash energy into the vehicle structure if they are at different heights, they don't respond as the design intended. "Our view is that they are essentially passenger cars so they should meet the same standards as passenger cars," Haley says.

The offset frontal test isn't the only blank spot on 4WD safety. They're also exempt from side impact tests. Why? The tests weren't designed with 4WDs in mind. Side impact tests model what happens when one passenger car hits another passenger car. But what happens when a conventional car is hit sideways by a 4WD? Or when a 4WD meets a solid object, perhaps a tree or a solid light-pole, side on? Occupants must place their faith in the manufacturer alone.

The 4WD was once a farm vehicle. Should it be reclassified given it rarely gets past the shopping centre carpark? That, at least in part, was what the Labor Party promised in the 1998 election campaign. The issue centred on the import tax excise at the time 4WDs had a 5% excise compared with 20% for passenger cars. Attacked by farmer groups and 4WD enthusiasts striving to protect their "primary producer" discounts and despite promising exemptions for those with genuine commercial needs Labor quietly dropped its promised reform after the election. (Car tariffs will now achieve parity by 2010 as part of the ACIS Administration Bill 2003.)

Tariff reform isn't quite enough. Later this year ANCAP will introduce a pole test to see how well 4WDs absorb side impacts from solid objects. But there's no plan to introduce a rollover test, despite American moves to rate 4WDs on their propensity to tip. And because the Australian Design Rules are essentially based on European standards, and 4WDs aren't exactly suited to downtown Brussels, there are no plans to change them to reflect the changing vehicle mix on our roads.

Australia should be following the US. Research quoted in The New Yorker found that SUVs generally resulted in more deaths than passenger cars. The Ford Explorer resulted in 88 driver deaths for every million Ford Explorers on the road. Compare this with the Honda Accord, which had 54 driver deaths per million cars or the Toyota Camry with 41. New Yorker journalist Malcolm Gladwell concluded that small cars "are safe because they make their drivers feel unsafe. SUVs are unsafe because they make their drivers feel safe. That feeling of safety isn't the solution; it's the problem."


The key drawbacks of 4WDs.

DESIGN: Many 4WDs are basically light trucks, designed for off-road use, and need to be driven using truck techniques: handling on corners can be vastly different; braking can require more roadway.

HEADLIGHTS: Sometimes fitted higher than in standard vehicles, they can cause glare and dazzle or blind oncoming drivers.

FRONT END: High bumpers, a feature of many 4WDs, and bullbars can cause serious damage to smaller cars.

CONSTRUCTION: Stiff separate frame is less able to absorb crash energy.

ROOF: With no standards on the strength of construction, weak roof can exacerbate damage and injury from rollovers.

SIZE: Vehicle size can restrict vision of other cars, particularly of traffic in front.

ROLLOVER: High profile and narrow track width, producing high centre of gravity, make some 4WDs prone to rollover.