Sydney Morning Herald – Friday 25 February 2005 - Drive

High but not so mighty

Author: PETER MCKAY

Four-wheel-drives with jacked-up suspension are dangerous, safety experts say, and there is no law to stop them, reports PETER MCKAY.

A senior road-safety advocate has slammed the Roads and Traffic Authority of NSW for its lax regulations on high-riding four-wheel-drives.

"Any regulatory authority that allows and certifies such raised vehicles needs to seriously reconsider its position and attitude towards road safety," says Raphael Grzebieta, president of the Australasian College of Road Safety and an associate professor of civil engineering at Melbourne's Monash University.

Four-wheel-drives are already over-represented in rollover crashes and Grzebieta is concerned that raising their centre of gravity makes them more susceptible to a rollover crash and would cause more serious injuries in a T-bone collision with a regular vehicle.

Grzebieta says the occupants of the smaller vehicle would experience massive head and chest injuries even at speeds as low as 30kmh. Similarly, in pedestrian impacts even a tall person would be dragged under the vehicle, resulting in major trauma.

According to research from insurer AAMI, most motorists are already in fear of heavyweight standard 4WDs. Seventy per cent of Australian drivers do not feel safe sharing the roads with them due to the arrogance and aggressive driving of their owners, says insurer AAMI. Almost half of the 1880 drivers who took part in a national survey wanted 4WDs banned from city streets, while 39 per cent of 4WD owners acknowledged their vehicles were probably dangerous to other motorists.

In NSW, there is little police can do to book such vehicles, despite their jacked-up suspensions and oversize wheels and tyres. "If the owners can produce an engineer's certificate, there's nothing we can do," said one senior highway patrol officer with 15 years' experience.

Despite global and national rollover data and mounting evidence from the Pedestrian Council of NSW - photos of 4WDs which have been raised dramatically - the RTA's chief executive Paul Forward defends the engineers' certification process and annual registration inspections.

"Handling ability during cornering most certainly would not have been checked by anyone," Grzebieta says. (Under the current system there is no requirement to test the cornering ability of a modified four-wheel-drive or its propensity to rollover.)

In response to criticisms of the engineer's certification process, the RTA offered Drive this response: "The RTA recognises that there are reasons why a vehicle may need to be raised - in these cases an engineer's certificate is required. If a vehicle has been raised and does not have an engineer's certificate, then a defect notice can be issued by police."

Privately, high-ranking police and highway patrol officers are concerned that the NSW registration system - which allows "freelance" engineers to certify modified vehicles - is open to abuse or interpretation.

"They're a cause for concern, especially with so many young P platers starting to get into these 4WDs," says another NSW highway patrol officer who didn't want to be identified. "The high centre of gravity, massive weight and their [drivers'] relative inexperience are an accident waiting to happen."

There is no law limiting how high a vehicle may be raised. Many of the tall-riding 4WDs appear to be modified with a longer suspension travel to perform better in challenging off-road conditions.

Vehicle suspensions may be varied by up to 50mm from the standard ride height without incurring the wrath of police or annual registration inspectors. The wheels and tyres must be within the vehicle's body line. Similarly, wheel and tyre widths and rolling circumferences must be within a small variation from standard. Beyond that, an engineer's certificate is needed.

Slav Stefaniuk, of 4WD Megastores, a retail chain selling 4WD accessory products, is sympathetic to concerns about modified off-roaders. But he says high-riding 4WDs should not be judged by the illegal work and actions of those who work outside the system.

"Most raised vehicles are not used every day - their long-travel suspensions and modified wheels and tyres are fitted for what are called 'rock-hopping' competitions held in controlled conditions in various off-road parks," Stefaniuk says. "Of course, changing the centre of gravity has an effect - the higher you lift them, the less controllable they may be unless other changes are made to compensate."

Stefaniuk says some high-riding vehicles have sophisticated suspension systems to offset the higher centre of gravity. "Owners will find it onerous to get these changes signed off, particularly where they relate to braking and cornering, unless they work."

He says engineers who certify the changes to vehicles have a technical and social responsibility that all modified vehicles steer and handle predictably and stop within safe distances.

Inspector Ron Dorrough, of the NSW Police, a specialist in interpreting and defining traffic regulations, says police may pull over the driver of a vehicle which has obvious modifications but if the driver can present a valid engineer's certificate, the vehicle will escape a defect notice.

This is the case even if the vehicle - re-engineered for specific off-road use in rural areas - is being driven in the city.

"How do they get engineer's certificates?" asks NRMA Insurance industry research manager Robert McDonald. "Or do they have friendly inspection stations to pass them?

"Some look like they'd fall over in a stiff breeze. You only have to observe how they handle, given their centre of gravity in relation to their tyre track - their stability must be atrocious.

"Their whole suspension geometry is so far removed from standard production vehicles and bumper bars conveniently moved to head height make a mockery of side-impact protection."

McDonald says most insurance companies won't cover suspension modifications to vehicles that exceed 50mm up or down.