Electric and hybrid vehicles have changed the way we move. They offer quieter, cleaner and more efficient driving. But that silence, while pleasant for drivers, can actually create a new kind of risk. If a car is too quiet, how do pedestrians and cyclists know it’s coming?
That’s where the AVAS system comes in. If you've never heard of it or you're curious about how it works and why it matters, here’s everything you need to know about the acoustic vehicle alerting system and how it's helping to make mobility safer.
What is the acoustic vehicle alerting system (AVAS) of cars?
The AVAS system stands for Acoustic Vehicle Alerting System. It is a safety feature built into electric and plug-in hybrid cars that emits a sound when the vehicle is moving at low speeds, typically under 20 km/h (around 12 mph).
Because these vehicles do not have a combustion engine, they make very little noise at low speeds or when reversing. That silence can be dangerous, especially for pedestrians who rely on sound to detect approaching vehicles, such as people with visual impairments, children or elderly individuals.
The acoustic vehicle alert system AVAS addresses this by generating an artificial sound that signals the presence of the vehicle. The goal is not to be loud, but to make sure the car is noticed in time.
How does the AVAS system work?
The AVAS system activates automatically when the vehicle is driving below a certain speed or when reversing. Once the vehicle exceeds approximately 20 km/h, the system turns off because tire and wind noise are generally enough to make the car detectable.
The sound is designed to resemble a soft engine noise or a futuristic tone and must vary in pitch depending on acceleration, deceleration or reversing. This variation helps people understand how fast the vehicle is going and whether it is approaching or moving away.
Each manufacturer can choose the specific sound, but it must comply with safety regulations to ensure that it is noticeable and informative without being unpleasant.
Why is the AVAS system important?
At first glance, the acoustic vehicle alerting system might seem like a minor detail, but it plays a vital role in improving road safety, especially in urban areas. Here is why the AVAS system matters:
- It helps protect vulnerable pedestrians, particularly those with visual or hearing impairments.
- It prevents accidents by making vehicles detectable before they are visible.
- It enhances safety in quiet environments such as residential areas, parking garages and pedestrian zones.
- It increases general awareness by providing an extra layer of communication between the car and people nearby.
The AVAS system ensures that quieter vehicles can still integrate safely into everyday traffic.
What do the regulations say about the AVAS system?
In recognition of its importance, governments and safety agencies around the world have introduced regulations to make AVAS systems mandatory. In the European Union, since July 2019, all new types of electric and hybrid vehicles must include an acoustic vehicle alerting system. Starting in July 2021, this requirement applies to all newly registered electric or plug-in hybrid vehicles. According to EU legislation:
- The system must activate automatically at speeds under 20 km/h or when reversing.
- The sound must be between 56 and 75 decibels, depending on the vehicle type.
- The pitch must change based on the car's movement to reflect acceleration or deceleration.
- The system must always be active and cannot be disabled by the driver.
Other countries, such as the United States and Japan, have similar laws with slight differences in volume levels and speed thresholds.
The AVAS system is more than a regulatory requirement. It is a practical and necessary feature that keeps pedestrians safe in a world where cars are becoming quieter and cleaner.
By producing a subtle but effective sound, the acoustic vehicle alert system AVAS ensures that electric and hybrid vehicles are still heard, even if they are not seen.
If you are considering switching to a more sustainable car, you will be glad to know that most new electric and hybrid models are equipped with AVAS technology. At Astara, you can explore a wide selection of eco-friendly vehicles designed to meet today’s safety and efficiency standards.