Active systems give the driver more control in dangerous situations. Simply put, active safety systems avoid or mitigate an accident pre-impact – so before it happens or contact is made. They are also known as ‘primary’ safety features.
Active safety systems: what are they and how do they work?
First wave of active safety systems
The first wave of active safety technology is already widely fitted to today’s passenger cars and commercial vehicles. Approximately 80-90% of the cars on Europe’s roads come equipped with technologies such as:
Anti-lock braking systems (ABS)
ABS systems help to prevent the wheels of a vehicle from locking when braking heavily, and enable the driver to keep steering.
Electronic stability control (ESC)
ESC helps to prevent a vehicle from skidding, and the driver from losing control while turning a corner. ESC technology can automatically activate the brakes to help steer the vehicle in the right direction.
Second wave of active safety
Now, a second wave of active safety measures is being introduced, using cutting-edge technology such as on-board sensors, radar, cameras, GPS and lasers.
The second wave of active safety innovation includes technologies such as:
Autonomous emergency braking (AEB)
AEB systems start braking automatically if a collision is imminent and the driver is not taking any action (or not fast enough). AEB can detect a potential collision and activate the brakes to avoid it, or at least mitigate its impact.
Lane departure warning (LDW)
LDW systems warn the driver if he or she leaves a marked lane without using the indicator, or if the vehicle is drifting out of its travel lane.
Lane keeping assistance (LKA)
LKA systems apply torque to the steering wheel or pressure to the brakes when a lane departure is about to occur.
Drowsiness and attention detection systems
These assess the driver’s alertness (for example by monitoring how long someone has been driving or by analysing how the steering wheel is being operated) and warn the driver to take a break when needed.
Speed limit information (SLI)
SLI systems inform the driver of the current speed limit by displaying it on the dashboard and/or navigation system. They use cameras to recognise road signs or use speed-limit data from the navigation system. Many SLI systems combine both.
Tyre pressure monitoring systems (TPMS)
TPMS monitor the air pressure of a vehicle’s tyres and report this information in real time to the driver, for example using a ‘low pressure’ warning light to indicate under-inflated tyres (which can cause accidents).
Intelligent speed assistance (ISA)
ISA systems can actively prevent drivers from exceeding the speed limit using road-sign recognition cameras and GPS-linked speed-limit databases.
If a collision is really unavoidable, active safety technology is also able to reduce its impact. Slowing the speed of a vehicle by a few kilometres before impact can save lives, for example. Indeed, active safety systems have the potential to not only reduce the number of accidents, but also can reduce the consequences of an accident if a collision cannot be avoided.