Car Safety Equipment

Vehicle Active Safety Equipment

As a company we get involved in driver training to improve drivers' skills in difficult situations. Modern vehicles are now fitted with safety equipment to aid the driver suchas: Anti Lock Brakes, Anti Skid devices, Traction Control and others all designed to help the driver should he/she make a mistake and begin to lose control of the vehicle. These devices are called active safety devices and are the subject of this month's newsletter.

Even if these systems are fitted to your car, it's essential that you understand a little about how they work and also consider some form of dynamics training to help you get the best out of them. 

Antilock Braking Systems (ABS)

This technology has been around for more than twenty years now and one of my first jobs working for a car manufacturer was to test and demonstrate this system on the Ford Scorpio in the mid eighties. The function of ABS is to stop the wheels from locking during heavy braking in slippery conditions.  It does this by releasing and then immediately applying brakes continuously on any wheel it feels is locking up. It can do this many times per second and so the driver feels only constant braking force.

When the system kicks in you will hear a rattling noise that can also be felt through the brake pedal, this can make some drivers think they have a vehicle problem.  

The benefit of the system is not to shorten the overall stopping distance of the vehicle as many people believe; in fact those early systems meant the car took a fair while longer to stop than a vehicle not fitted with an ABS system.

The benefit of having ABS fitted on your car is that it gives you the ability to steer around an obstacle whilst braking in an emergency. Such is the safety benefit of ABS that European legislation now insists that all new cars are fitted with ABS as standard. Although the system has obvious safety benefits I believe that a certain amount of driver training and conditioning will allow the driver to extract the most from the system.  As a driver faced with an emergency hazard may well fixate on an obstacle and not swerve around it for fear of the car entering a skid, when in fact the ABS system would allow the car to steer safely around the obstacle.

Traction Control (ASR)

This system uses the ABS sensors to detect a small amount of wheel spin, it's also connected to the engine management system allowing it to reduce the power and stop the wheels slipping.  This system also has the benefit of reducing the chances of a skid caused by applying too much power whilst applying steering lock (power sliding).  If the TCA warning light is flashing on, for example say when you are negotiating a roundabout in the rain, the system has reduced the power to the drive wheels as you are being too heavy footed! Take it as a warning the surface is more slippery than you thought and you should adjust your driving to the conditions!

Electronic Stability Program (ESP)

This technology is relatively new and builds on the ABS technology using the wheel sensors and a sensor in the steering system to detect when the car is skidding and not following the intended path of the driver. Early systems were quite obtrusive and tended to kick in rather early, and thus were not popular with drivers who had a more sporty driving style. Many drivers would therefore, turn off the ESP system as they felt it interrupted their driving too much and thus they lost any benefit that the system would give them in an emergency. Modern ESP systems are very much more intuitive and have settings to suit the particular vehicle, for instance, if you have a high performance vehicle fitted with ESP, it's likely to be set to allow the car to move around to a fair degree before it cuts in to bring the car back under control. The switch on the dashboard which is fitted to allow the driver to turn the system off, is only there so the system can be turned off if the driver becomes stuck in mud or snow as in these situations the system will not allow the car to spin its wheels. Having tried many of the modern ESP systems I can see no reason to turn them off if your not stuck in mud or snow, they are a great safety device and can work very effectively in the background should they be needed.

Whereas traction control can only reduce the engine power when it detects the car is skidding, ESP systems use the brakes individually on each wheel in a very clever way to bring the car back in control. The system also attempts to keep the car travelling in the direction that the steering is pointing therefore it important not to over react to the skid. 

Important

So as you can see active safety systems represent a very real safety benefit for road travel. However it is important that drivers are aware of what systems are fitted to the car that they are driving. When you are about to drive a car that is new to you spend a few seconds looking at the indicator lights on the dashboard to see what active safety systems are (or are not!) fitted. Also consider having some vehicle dynamic or skid control training which involves using ABS and teaches a vehicle control technique that compliments other active safety systems. That way if you do get into a tricky situation, you will have a better idea how to react to it and exploit these active safety systems.

Safe Journeys.

Lionel Firn (Cheif Instructor)