Understanding vehicle safety systems

Modern cars are fitted with a variety of innovative safety systems, but what exactly do they all do?

Reuben Van Niekerk
Traction control
Cruise control
car safety

One of the biggest areas of vehicle development in the last 15 years has been in terms of safety. Cars are now safer than ever both in terms of keeping occupants safe when you are involved in an accident as well as preventing you from getting into a dangerous situation in the first place.


Long lists of acronyms regarding vehicle safety are often included in new car reviews and vehicle specification sheets but what do these systems actually do and how do they keep you safe?



ABS or Anti-lock braking is an anti skid braking system that prevents the cars wheels from skidding during harsh braking. The system does this by applying maximum braking force and then releasing the brakes for a split second before applying maximum braking again a couple of times per second in order to maintain traction with the road surface.


The affect of ABS can be felt by the slight pulsating of the brake pedal under harsh braking. Apart from preventing skidding, ABS also significantly reduces stopping distances of braking on good surfaces and prevents the flat spotting of tyres that can occur when a tyre locks up under braking.


Traction Control

Traction control works in the background to aid acceleration on slippery surfaces by limiting the amount of power in relation to the amount of grip the tyre has and in doing so preventing wheel spin. It is most effective when accelerating on slippery surfaces such as gravel or wet roads.


Stability Control

ESC, ESP, or DTC depending on the manufacturer are all forms of Electronic stability control. This computer-controlled technology improves vehicle stability by detecting and reducing skidding. When the system detects loss of directional control, brakes at individual wheels are applied to pull the car in line once again. Some systems also reduce engine output until control is regained.


Cruise Control

Cruise control maintains a constant predetermined speed without the driver having to keep their foot on the accelerator or use the brake. This is particularly useful on long journeys where keeping a constant speed aids in maintaining a good average speed and also prevents accidental exceeding of the speed limit. The driver still needs to maintain control of the steering wheel and the system turns off as soon as the driver touches the brake or accelerator.


A recent development includes distance control, allowing the driver to set the speed as well as the distance that you would like to keep between yourself and the car you are following. The vehicle then automatically monitors this distance using radar camera systems and brakes and accelerates automatically in order to maintain that distance and the speed as per the drivers setting.


Hill descent control

This system is mostly found in four-wheel drive vehicles and SUVs. It is very dangerous to use the vehicles brakes when descending extremely steep gradients. Hill descent control ensures that the vehicle safely descends gradients by controlling the speed with engine braking and controlled braking. Speed can be adjusted but is normally between 4 and 8km/h.


Autonomous Emergency braking

Using a variety of sensors or cameras Autonomous Emergency Braking will start braking automatically if it detects that a collision is imminent and the driver is not taking any action or is not reacting quickly enough. This system helps avoid collisions or mitigate their impact


Lane departure warning

Lane departure warning systems will warn the driver if they are leaving their lane without using an indicator or if the vehicle is drifting out of the lane. This system is very often coupled with a Blind Spot warning system which aims to make a driver aware of another vehicle in their blind spot by the illumination of a light in the side mirror followed by an audible warning if the driver then puts on their indicator or steers in the direction of an occupied blind spot.


Read "Car Hack: Understanding Dashboard Warning lights" here.