AVAS
The Acoustic Vehicle Alerting System (AVAS) is an acoustic warning or driving noise system that generates an artificial noise in electric vehicles to alert other road users, especially pedestrians, cyclists, children, or people with visual impairments, to the approaching vehicle. AVAS is an externally audible warning signal that complements the virtually silent movement of electric and hybrid vehicles at low speeds.
Purpose and background
Electric vehicles are often very quiet at low speeds, which makes it difficult for uninvolved persons to hear them and can potentially lead to dangerous situations. AVAS was developed to close this safety gap and increase road safety.
How it works
An AVAS system typically consists of a loudspeaker, electronic control unit, and a connection to the vehicle’s electronics. It generates an audible, continuous driving noise that is adjusted in pitch and volume to the speed of the vehicle. When certain speeds are exceeded (often around 20 km/h in the EU), the system switches off because tire and wind noise provide sufficient acoustic warning. At the same time, a separate tone can be used for reversing.
Legal requirements
In many regions, including the European Union, AVAS is mandatory for low-noise vehicles. In the EU, Regulation No. 540/2014 stipulates that newly registered electric and hybrid vehicles must be equipped with an AVAS that emits audible warning signals at low speeds. The legal requirements include minimum and maximum values for the volume of the signal as well as requirements for its function.
Sound design
The regulations specify general conditions (e.g., volume and activation range), but not the exact sound. Manufacturers can therefore incorporate their own sound characteristics, giving different models distinctive acoustic signatures. On the one hand, this opens up creative sound design approaches, but on the other hand, it raises discussions about traffic and environmental noise.
Retrofitting
While AVAS equipment is mandatory for new vehicles, in many regions there is no general legal obligation to retrofit older electric vehicles. Nevertheless, retrofitting with suitable modules is possible and can significantly increase safety, especially in urban environments or on construction site vehicles such as electric forklifts (e.g., with special alarm or warning systems such as EVAS/E-VAS, which generate acoustic warning signals for electrically powered commercial vehicles).
In brief
AVAS is a legally required acoustic warning system for quiet vehicles that generates an artificial driving noise to improve road safety. It activates at low speeds and can also be retrofitted to suitable electric vehicles.