Index
What is active and passive safety in a vehicle?
Active safety covers all the systems designed to prevent accidents. These are the guardians that help you maintain control of your vehicle at all times. Passive safety, on the other hand, groups together the devices that come into play once an accident has already occurred, with the aim of minimising injuries to the occupants.
Understanding the difference between active and passive safety will help you make better-informed decisions about your vehicle's maintenance and what to look for when choosing your next car.
The difference between active and passive safety
We've already touched on this, but let's break it down in more detail.
Active safety
Active safety devices work preventively, before an accident happens. They operate continuously, improving your control of the vehicle, your visibility, optimising braking and alerting you to potential hazards.
Passive safety
Passive safety elements come into action during or after an impact. They remain inactive until a collision is detected, then trigger within fractions of a second to protect the occupants, absorbing impact energy and preventing serious injury.
Active safety devices in cars
Let's look at some examples of active safety in practice.
ABS brakes
The anti-lock braking system (ABS) prevents the wheels from locking up during emergency braking, allowing you to maintain steering control. It automatically modulates braking pressure up to 15 times per second, preventing skidding and giving you the ability to swerve around obstacles.
Electronic stability control (ESP)
ESP detects when the vehicle is losing stability and automatically intervenes by braking specific wheels and reducing engine power to regain control. It is particularly useful when cornering or performing evasive manoeuvres.
Lane departure warning system (LDW)
LDW uses cameras to monitor road markings and alerts you if it detects that you are drifting out of your lane without indicating. More advanced systems (LKA) apply automatic steering corrections.
Emergency braking assistance
Using radar sensors or cameras, this system detects obstacles in your path. If there is a risk of collision and you do not react, it triggers alerts and, if necessary, automatically applies the brakes to avoid the impact or reduce its severity.
Tyres and lighting systems
Well-maintained tyres are the only point of contact with the road surface. Keeping the correct tyre pressure and checking for wear is essential. Lighting systems (LED, adaptive) allow you to see and be seen, significantly improving night-time visibility.
Passive safety elements in cars
Now that the active safety devices are clear, let's take a closer look at the passive ones.
Seat belts
The seat belt remains the single most effective safety element, reducing the risk of death in frontal collisions by 75%. Modern belts incorporate pretensioners that automatically tighten the strap in milliseconds, along with load limiters that prevent chest injuries.
Airbags
Airbags deploy between 20 and 30 milliseconds after detecting an impact. Today's vehicles feature multiple airbags: frontal, side, curtain and knee, always working in conjunction with the seat belts.
Crumple zones
Modern cars have programmed crumple zones at the front and rear, alongside a rigid safety cell in the passenger compartment. The deformable zones absorb the energy of the impact while the cabin maintains its structural integrity.
Headrests
Essential for preventing whiplash in rear-end collisions, active headrests move forward and upward to reduce the distance to the head, minimising cervical injuries.
Child restraint systems
Mandatory for children under 135 cm, these are designed according to the child's weight and age. ISOFIX systems make installation safer and reduce the risk of fitting errors.
The importance of combining active and passive safety
Active and passive safety work together as an integrated ecosystem. Imagine driving on a wet road when a vehicle brakes sharply in front of you: ABS and ESP work to prevent a collision (active safety), but if impact is unavoidable, pretensioners, airbags and crumple zones minimise the consequences (passive safety). This combined effort can make the difference between walking away unharmed and suffering serious injuries.
How has safety in modern cars evolved?
Vehicle safety systems are, of course, not static. They have evolved steadily over the years and will continue to do so.
Emerging technology in active safety
ADAS systems include adaptive cruise control, blind spot assistance, sign recognition and semi-autonomous driving systems. V2X connectivity will enable communication between vehicles and infrastructure, reducing accidents even further.
Innovations in passive safety
Notable advances include external airbags for pedestrians, central airbags between seats, seat belts with integrated airbags, and ultra-lightweight, high-strength materials that absorb energy more effectively without adding extra weight.
Frequently asked questions about active and passive safety
Finally, here are answers to the most common questions, so you have a clear picture of vehicle safety systems.
Which is more important, active or passive safety?
Both are equally important and complement each other. Vehicles that score well in both areas have significantly lower fatality rates.
Which active safety devices are legally required in the EU?
Since July 2022, all new vehicles must include: an emergency braking system, a lane-keeping assistant, fatigue detection, a reversing alert, a black box and an intelligent speed limiter.
How much do a car's materials affect passive safety?
Materials are absolutely fundamental. Manufacturers use ultra-high-strength steels in strategic areas and materials designed to absorb energy through controlled deformation in others, optimising occupant protection.
Does active safety reduce the cost of car insurance?
Yes, many insurers offer discounts of between 5% and 15% for vehicles equipped with advanced active safety systems, as they statistically reduce the likelihood of accidents.
Technological progress has made today's vehicles the safest in history. Yet no system can replace efficient, responsible driving that respects the rules of the road.
Keeping your vehicle in perfect condition through regular servicing, tyre checks and brake system inspections are investments that could save your life. Road safety is a shared responsibility where technology and your attitude behind the wheel must work in perfect harmony. Because what matters is not just reaching your destination, but always arriving safe and sound.
Find out more
For a more detailed look at the regulations surrounding the emergency braking system, refer to this official document on the EU regulation: https://www.boe.es/buscar/doc.php?id=DOUE-L-2019-81951#:~:text=Reglamento%20(UE)%202019/2144%20del%20Parlamento%20Europeo%20y%20del,n%C2%BA%201230/2012%20y%20(UE)%202015/166%20de%20la%20Comisi%C3%B3n
