Friday, January 2, 2009

Four-wheel drives (4WD)

What you need to know about owning a 4WD

If you think you've seen a lot more 4WD recreational vehicles on the road recently, you'd be right. Indications are that the numbers of 4WD recreational vehicles on New Zealand roads is steadily increasing.

However if you are considering buying a 4WD recreational vehicle you must be aware that they are not cars and they do handle differently. Research results suggest that 4WD vehicles can be safer than passenger cars in certain circumstances but less safe in others.

For instance 4WD recreational vehicles have been found to be 'aggressive' towards other road users. This means that when they crash into another road user they deal out a highly disproportionate amount of damage to the occupants of other cars, pedestrians, motorcyclists and cyclists.

How 4WDs are different from others types of vehicles...

  • Drivers have a higher seating position and better vision of the road. The vehicle may also have greater height and weight, and offroad capability.
  • A 4WD recreational vehicle also has a higher centre of gravity and a combination of tyres and long travel suspension that are a compromise between on-road and off-road capability. The vehicle may not hug the road as well as a driver is used to and it is likely to have greater mass than a car to slow down.
  • Research shows 4WD recreational vehicles are more likely to roll over than other light vehicles and this is a common cause of 4WD crashes in New Zealand and overseas. The chances of a vehicle rolling over also increase with each additional passenger. A fully laden 4WD is more likely to roll after a sudden evasive manoeuvre or fast cornering than a 4WD containing only a driver.
  • In multiple-vehicle collisions, heavier 4WD recreational vehicles can do a serious amount of damage to people in other vehicles. And some older 4WD imports may not have the built-in crumple zones that modern cars benefit from.
  • Rollover crashes have been identified as a major cause of spinal injury. An Australian study found spinal injuries related to the structural strength of the roof which was often inadequate in 4WD type vehicles.
  • In terms of crashworthiness, studies have found 4WDs fared better than medium and small cars, vans and commercial vehicles. However, overall, luxury and large cars do a better job of preventing severe injury to the driver.
  • All of this means 4WD drivers are wise to take more care, and modify their driving style from how they would drive a car. See the driving tips below.

4WDs are safest for the occupants when they have:

  • anti-rolling design features
  • strong roof support pillars
  • ABS brakes
  • dual airbags
  • side intrusion bars
  • side air bags
  • headrests for all seating positions, and
  • a lap-sash belt for the middle passenger in the second row of seats.

They are safest for other road users when they:

  • do not have bull bars
  • do have crumple zones, and
  • are driven by people who have been trained in their use.

If you do buy a 4WD carefully read these driving tips

  • Go around corners MORE SLOWLY than you would in a car - the higher centre of gravity means your 4WD vehicle handles differently, and you need to allow for this.
  • As with any vehicle, always wear a well-adjusted safety belt. 4WD recreational vehicles are more likely than other vehicles to roll over in a crash - wearing a safety belt is the best way to protect your neck and spine. Safety belts also keep you in the vehicle - anyone thrown from a vehicle is highly unlikely to survive if their vehicle rolls onto them.
  • Be very mindful of other road users given the greater degree of injuries 4WD recreational vehicles inflict.
  • Place heavy items inside the vehicle behind a cargo barrier, and only put light items on a roof rack.
  • Increase your following distance - it may take you longer to stop than in a car.
  • Remember that while the size and shape of your 4WD may improve your field of vision, it can reduce the field of vision for other road users.
  • Because you have a higher centre of gravity, drive defensively - you are much safer if you never have to make any sudden swerving or evasive moves.
  • If you don't need bull bars for off-road travel, don't have them fitted - they can be lethal for other road users.

Most importantly...

  • Remember that you are not any safer in your 4WD recreational vehicle than you would be in a car - appreciate the handling characteristics of your 4WD and modify your driving style accordingly.

Going off road?

If you are going to use your 4WD off-road it makes sense to join a four wheel drive club in your area. Ask your local dealer or a specialist off-road training provider for more information.

No comments:

Post a Comment