What makes a car safe? – Part 2

Car Safety Car Technology
Car safety - what makes a car safe? BMW M5 demonstrates controlled oversteer

In the second of a three-part blog series on car safety, The Car Expert looks at the ‘active safety’ features of modern cars and how advanced electronics can help you avoid an accident.

In my last blog on car safety, 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 has been raised by programs such as EuroNCAP, but obviously not having an accident at all is preferable even to a very small accident.

Active safety systems are amazing

Modern cars have a range of highly advanced electronic systems which help a driver to maintain control in an emergency situation and reduce the chance of having a crash. Even a basic new car will come with anti-lock brakes (ABS) and usually some form of Electronic Stabilisation Program (ESP, or sometimes referred to as ESC, VDC, PSM or other acronyms depending on the manufacturer).

ABS prevents the brakes locking when you jump hard on the pedal, so that you can still steer rather than sliding helplessly straight on. 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’s all working well, you barely even notice anything is happening.

Many modern cars have a whole host of 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 behaviour, 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 car safety technology are now available which take this even further. Blind spot monitors use cameras to keep an eye on your blind spots and warn you if you are about to move over in front of another car, or help 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 to a complete stop if necessary. Until recently, these systems were only available in high-end luxury cars, but are now becoming more widespread among mainstream models.

Good design is as important as electronic trickery

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 weight 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 behaviour and gives the driver confidence when action needs to be taken. Predictable behaviour 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.

Car safety includes the driver

When test driving a car that you are looking to buy, it is important to consider how comfortable you find the car, and how easy it is to see ahead, behind and to the sides. Every person is different, so the position of seat, pillars and mirrors will affect everyone differently, and that will affect how you are able to respond to an emergency situation. Make sure you give the brakes a good shove (make sure there’s nothing behind you and that the other people in the car know what you’re about to do!) so you can get a feeling for how the pedal responds. Check your blind spots, check your mirrors, check how well you can see traffic – especially bikes – at roundabouts and so on.  If you are looking at a used car, check the tyres to see how new they are and whether they are a reputable brand or a brand you’ve never heard of.

Avoiding a car crash is better than surviving a car crash

Ultimately, no car can overcome the laws of physics. If you pile into a corner at far too great a speed on a wet road, then it doesn’t matter whether your car has ABS, ESP, ASR or any other fancy electronic avoidance systems – you will still be testing out the airbags. And you don’t really want to have to do that.

In the last part of the car safety-themed blog trilogy, I will be talking about what you can do to make your current car safer. Car safety is an important and quite complex topic, so if you have any questions you can ask them in our forum or in the comments below.

You should also read: What makes a car safe? – Part 1: The Car Expert looks at ‘passive safety’ and how a car behaves in a crash.

This article was first published in November 2011, and has been updated in July 2015 for freshness, accuracy and relevance.

Stuart Masson

Stuart is the Editor of The Car Expert, which he founded in 2011, and our new sister site The Van Expert. Originally from Australia, Stuart has had a passion for cars and the car industry for over thirty years. He spent a decade in automotive retail, and now works tirelessly to help car buyers by providing independent and impartial advice.


  1. hi, can you tell me the difference between ESP and ESC? jason

    • Stuart Masson

      Hi Jason,

      ESP and ESC are the same thing. The most common acronym is ESP – Electronic Stabilisation Program. ESC (electronic stability control), VDC (Vehicle Dynamic Control) and various other titles are used by different manufacturers to describe the same thing. Most of the manufacturers use hardware supplied by Bosch and then calibrate it to suit their models.

      Hope this helps,


  2. Can you settle an argument for me and a mate? Does traction control apply the brakes or cut the throttle to retard acceleration?

    • Stuart Masson

      Hi Richard,

      You may both be right! If a car has an electronic throttle (which is most cars these days) instead of an old-style mechanical throttle cable, then the car’s on-board computer can either reduce throttle or apply brakes to stop a wheel from spinning. Usually if it’s only one wheel spinning it will apply the brake to that individual wheel, whereas if both wheels are spinning it is more likely to reduce throttle as well.



  3. I don’t trust NCAP scores. A big car with 2 stars will crush a small car with 5 stars. I know which car Id rather be in when that happens.

  4. I always thought that ESP and other stability systems were a bit of a joke or only useful for poor drivers, but I got to go to an Audi Drive Day a few years ago, an s was amazed at how good the systems are. Not only do you feel safer, but it helps you maintain your concentration so you don’t get as tired.

  5. What’s your take on smart cruise controls which keep you at a distance from the car in front? I don’t think I could trust the car to do that…

  6. Jaguar Land Rover is working on a new safety research projects to reduce the number of accidents caused by drivers that are distracted or not concentrating on the road.The research project named ‘Sixth Sense’ makes use of advanced technology to monitor the driver’s brain waves, respiration levels and heart rate which identifies the driver stress, fatigue and lack of concentration


What are your thoughts? Let us know below.

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