Car safety
Modern vehicles contain a range of safety features designed to help prevent collisions and reduce the severity of injuries when crashes occur. These include braking technologies, tyres, vehicle lighting, airbags, seatbelts and head restraints. Understanding how these systems work and ensuring they are properly maintained can significantly improve safety for drivers and passengers.
Vehicle safety systems explained
Modern vehicles use a combination of technologies designed to:
- Prevent collisions
- Help drivers maintain control
- Protect occupants during a crash
- Reduce injury severity when collisions occur
These systems work together and deliver the greatest benefit when drivers use them correctly and maintain their vehicles properly.
Electronic braking systems
Electronic braking systems help drivers retain control of their vehicles during emergency situations and can reduce stopping distances.
Brake Assist (BA)
Brake Assist, sometimes known as Emergency Brake Assist (EBA), helps ensure maximum braking force is applied during emergency braking.
It works by detecting how quickly the brake pedal is pressed. If the system recognises an emergency braking situation but determines the driver has not applied maximum braking force, it automatically increases brake pressure.
Autonomous Emergency Braking (AEB)
Autonomous Emergency Braking is designed to prevent or reduce the severity of collisions.
Using sensors, radar, cameras or laser technology, the system:
- Detects hazards ahead
- Warns the driver
- Applies the brakes if necessary
- Can identify vehicles, pedestrians and cyclists on some systems
Although AEB cannot prevent every collision, it can significantly reduce impact speeds and injury severity.
As of May 2022, all new cars sold in the UK must be fitted with AEB as standard.
Anti-Lock Braking Systems (ABS)
ABS prevents wheels from locking during heavy braking.
Benefits include:
- Shorter stopping distances in some conditions
- Improved steering control
- Reduced risk of skidding
- Greater vehicle stability during emergency braking
If ABS activates, drivers should maintain firm pressure on the brake pedal and allow the system to operate. Pedal vibration is normal.
Electronic Stability Control (ESC)
ESC helps prevent loss of control by detecting skids and automatically applying braking to individual wheels while reducing engine power where necessary.
Since 2014, ESC has been fitted as standard to new cars sold in the UK and Europe.
Tyre safety
Tyres are the only part of a vehicle that makes contact with the road. Their condition has a major impact on braking, steering and grip.
In Great Britain in 2024, defective tyres were identified as a contributory factor in hundreds of road casualties.
Check tyre pressure regularly
Incorrect tyre pressure can:
- Increase stopping distances
- Reduce vehicle control
- Increase tyre wear
- Increase the likelihood of tyre failure
Tyre pressures should always be checked when tyres are cold and adjusted to the manufacturer's recommended settings.
Tread depth
The legal minimum tread depth for cars is:
1.6mm across the central three-quarters of the tread around the entire circumference of the tyre.
RoSPA recommends replacement well before this point, ideally when tyres reach around 3mm of tread depth.
Ways to check tyre tread
- Tread wear indicators
- 20p coin test
- Tyre tread depth gauge
Seasonal tyres
Different tyre types are designed for different conditions:
Summer tyres
Optimised for warmer temperatures and dry roads.
Winter tyres
Designed for colder temperatures, snow, ice and wet roads.
All-season tyres
A compromise between summer and winter performance and often well suited to UK conditions.
Tyre Pressure Monitoring Systems (TPMS)
TPMS alerts drivers when tyre pressures fall below recommended levels. These systems are particularly valuable because under-inflation is often difficult to detect visually.
Vehicle lighting
Vehicle lighting helps drivers see and be seen, particularly during darkness and poor weather conditions.
When must you use headlights?
The Highway Code requires drivers to:
- Use lights between sunset and sunrise
- Use headlights when visibility is seriously reduced
- Avoid causing glare or dazzle to other road users
Modern lighting technologies
Daytime Running Lights (DRL)
DRLs improve vehicle visibility during daylight hours and are fitted to modern vehicles as standard.
Adaptive Lighting Systems
These systems adjust headlight beams to:
- Improve visibility through bends
- Respond to speed
- Reduce glare
- Automatically manage high beam where fitted
LED, Halogen and Xenon Lights
Modern vehicles commonly use:
- Halogen lamps
- Xenon (HID) lamps
- LED lighting systems
Each offers different performance characteristics in terms of brightness, efficiency and lifespan.
Headlight glare
Headlight glare remains a common concern affecting drivers, cyclists and pedestrians. Misaligned headlights and incorrect loading can increase the risk of dazzle.
Drivers should:
- Check headlight alignment
- Adjust headlight settings when carrying heavy loads
- Avoid inappropriate use of full beam and fog lights
Head restraints and whiplash protection
Head restraints are designed to reduce head movement during a collision and help prevent whiplash injuries.
How to adjust a head restraint
For maximum protection:
- The top of the restraint should be level with the top of your head
- It should be positioned as close as possible to the back of your head
Poorly adjusted head restraints can significantly reduce protection in a rear-end collision.
Advanced whiplash protection
Modern vehicles may include:
Active Head Restraints
Move forward during a rear impact to support the head sooner.
WHIPS Seats
Whiplash Protection Systems are designed to control the movement of the occupant's body and head during rear impacts.
Airbags
Airbags are designed to work alongside seatbelts to reduce injury severity during collisions. They are not a replacement for seatbelts.
How airbags work
Airbags inflate and deflate extremely rapidly during a collision, cushioning occupants and reducing contact with hard surfaces such as:
- Steering wheels
- Dashboards
- Vehicle interiors
Sensors determine whether deployment is required based on the severity and direction of impact.
Important airbag safety advice
Child seats
Never use a rear-facing child seat in a front passenger seat with an active airbag.
Driver position
Drivers should:
- Sit as far back as practical
- Maintain good seatbelt positioning
- Keep hands at the recommended positions on the steering wheel
Pregnancy
Pregnant occupants should maximise distance from the airbag deployment zone while continuing to wear seatbelts correctly.
Seatbelts
Seatbelts remain one of the most effective vehicle safety measures ever developed. They help prevent occupants being thrown around or ejected from vehicles during collisions.
Wearing a seatbelt correctly
A seatbelt should:
- Be worn tight without slack
- Sit across the pelvis, not the stomach
- Cross the centre of the shoulder
- Never be twisted or obstructed
Pregnant women and seatbelts
Pregnant women should continue to wear seatbelts.
The lap portion should sit below the bump across the pelvis, while the diagonal strap should pass between the breasts and across the shoulder.
Children and seatbelts
Seatbelts are designed for adults, rather than children. Children must use an appropriate child car seat until:
- They are 135cm tall, or
- They are 12 years old
Whichever comes first.
Seat belt law at-a-glance
| Front Seats | Rear Seats | Who is responsible? | |
|---|---|---|---|
|
Driver |
Seat belt must be worn if fitted |
- |
Driver |
|
Child up to 3 Years of Age |
Correct child restraint must be used |
Correct child restraint must be used If one is not available in a licensed taxi or private hire vehicle, the child may travel unrestrained. |
Driver |
|
Child Aged 3 To 11 and Under 135cm in height (about 4.5 Feet) |
Correct child restraint must be used |
Correct child restraint must be used if seat belts are fitted If a child seat is not available, a child may travel using just the seat belt in these situations:
|
Driver |
|
Child Aged 12 or 13 years or Younger Child 135cm or taller |
Adult seat belt must be worn if fitted |
Adult seat belt must be worn if fitted |
Driver |
|
Passengers aged 14 years and over |
Seatbelt must be worn if fitted |
Seatbelt must be worn if fitted |
Passenger |