In my last article, I explained the difference between a car’s ‘passive safety’ (the ability to protect you in the event of an accident) and its ‘active safety’ (the ability to help you avoid having an accident in the first place).
Both are equally important although active safety tends to be less understood and thus often overlooked. The profile of passive safety in modern cars has been raised by programs such as EuroNCAP, but obviously not having an accident at all is preferable even to a very small accident.
Modern cars have a whole range of advanced electronic systems which help a driver to maintain control of the car in an emergency situation and reduce the chance of having a crash. Even the most basic new car will come with anti-lock brakes (ABS) and usually some form of Electronic Stabilisation Program (ESP, or sometimes referred to as VDC, PASM or other acronyms depending on the manufacturer).
ABS prevents the brakes locking when you jump on the pedal, so that you can still steer rather than sliding straight ahead. ESP is a very clever system which recognises where you are trying to steer and whether or not the car is actually going that way. If the car’s direction doesn’t match where you are trying to steer it, ESP can brake individual wheels on the car and even cut throttle if necessary to help the car go where you are pointing it. It is very helpful in slippery conditions where the car wants to slide straight on instead of turning (understeer) or spin around backwards (oversteer). If it is all working well, you don’t even notice anything is happening.
Many modern cars have a whole host of electronic systems in addition to the two examples above which can help make the car ‘safer’ to drive. These systems can make the car more predictable in its behavior, slow it down slightly to allow tyres to maintain grip, even apply different levels of braking to each wheel to keep the car balanced. All of these things make it easier for the driver to maintain control of the car, and therefore less likely to have an accident.
Some very advanced technology is available in luxury cars which takes this even further. Blind spot monitors use cameras to keep an eye on your blind spot and warn you if you are about to move over in front of another car, or helps to stop the car drift out of its lane. Some cars can ‘recognise’ speed limit signs and flash you a reminder. Night vision technology is available to identify pedestrians outside of your headlights’ range. There are advanced cruise control systems which not only maintain your speed, but can speed up or slow down to follow the car in front and even brake the car from 150mph to a complete stop if necessary.
Last year I drove an Audi A8 in Germany, on autobahns and around towns as part of an Audi training program. Over a 20-ish mile drive route in a convoy of cars, I went from 60mph to 150mph (unrestricted autobahn, not through city streets) to a complete stop to 140mph and back to a complete stop, overtaking other cars, following other cars, got stuck behind a truck for a while, trundled through a village and eventually pulled into a car park and stopped. At no point for more than 20 miles did I touch either the brake or the accelerator. Yet the car had behaved itself perfectly, faithfully following the car in front without ever getting too close. For the first half of the journey, my foot was hovering right over the brake pedal just in case, but the car’s systems were clever enough to ‘read’ the traffic conditions and respond accordingly. Once I got over the surreal feeling of a car accelerating to over 150mph (250km/h in the metric world) and stopping from that speed with no pedal input from me, it was actually a very comfortable drive and made the trip more relaxing. The system used two radar units, a camera, the parking sensors, the satnav system and a powerful computer system to gather and process a huge amount of information and make split-second decisions all along the way.
But active safety isn’t just about electronics. Any aspect of a car’s design or engineering which helps a driver avoid an accident is an active safety feature. The thickness and placement of windscreen pillars, for example, has an important effect on a driver’s ability to see oncoming traffics at roundabouts. A lighter car will respond more nimbly to changes of direction (say, swerving to avoid a dog on the road) than a heavy car. Modern tyres are much better at dispersing water in heavy rain, making it less likely that you will slide off the road. More sophisticated suspension systems help cars stay better balanced on the road, even at high speeds or when towing heavy loads.
Ultimately, an ‘actively safe’ car will be one which is easy to drive, predictable in its behavior and gives the driver confidence when action needs to be taken. Predictable behavior is safe, so that a driver knows exactly how a car is going to respond and will instinctively steer and/or brake when a problem presents itself. A car that behaves unpredictably leads to a driver acting hesitantly and not taking enough action to avoid an accident.