my car

When you apply your brakes, you want your car to slow down, but you also want to be sure that you don't lose control of the vehicle. For this reason, many modern cars are fitted with anti-lock braking systems (ABS) which allow the driver to stop the car in the shortest distance possible without skidding or spinning out of control. They also allow the driver to continue to steer the vehicle while the brakes are applied.

So, cars fitted with ABS are inherently safer. But is ABS achieving its potential? RACV was concerned about overseas research which suggested that it wasn't, so we commissioned Monash University Accident Research Centre (MUARC) to examine the Australian experience. MUARC analysed the crash records for a number of models that came equipped both with ABS and without it, and compared their actual crash involvement.

The results were mixed, and rather disturbing. For multi-vehicle crashes, ABS-equipped vehicles were less likely to be involved (by about 18%) compared with the same model without ABS. However, for single-vehicle run-off-road crashes, e.g. leaving the road on a bend, ABS vehicles were over-involved by about 35% compared with the equivalent model without ABS. This increased involvement of ABS-equipped vehicles in run-off-road crashes is particularly concerning.

Why should this be so? Why should an inherently safer vehicle be over-involved in certain types of crash? The answer probably lies in the way in which ABS is used - or misused - by the driver.

ABS feels different, particularly under heavy braking; the car may seem to shudder or vibrate. This is explained by the way ABS works. It monitors the speed of each individual wheel, and when the control unit detects the onset of brake lock-up, it momentarily reduces brake hydraulic pressure to that wheel. This adjustment can be made many times in the space of a second, which the driver will feel as a pulsing sensation through the brake pedal.

Perhaps some drivers, not having experienced this, may respond by taking their foot off the brake. In fact, the correct response is to maintain braking pressure. In other words, push as hard as possible when a quick stop is necessary - " Stomp and steer!" ABS will do the rest.

Of course, you need to know if your car is fitted with ABS, so check the owner's manual. And read the instructions in the manual, as most will provide driving hints about how best to use the brakes.

Just as importantly, drivers must not become overconfident in the mistaken belief that their ABS brakes will get them out of any trouble. In fact, stopping distances and travelling speeds may not be any different between ABS and non-ABS equipped vehicles. Indeed, on some surfaces such as loose gravel, an ABS-equipped car may have a longer braking distance.

There are other braking and stability technologies starting to come on the market (see above), and the MUARC research indicated many of these have the potential to provide substantial benefits. Currently, these are seen mostly on the more expensive luxury models, but they will likely filter down to more popular models soon. RACV will continue to monitor the potential of these technologies.

RACV is confident about the potential for ABS to prevent crashes, and encourages motorists to choose ABS-equipped vehicles. But drivers should consider the warnings and tips discussed here to make the most of the technology.