Vietnam Registry Proposes Mandatory Acoustic Vehicle Alerting Systems for Electric Vehicles to Enhance Pedestrian Safety

The Vietnam Registry is currently soliciting public and expert feedback on a comprehensive update to national technical regulations regarding vehicle inspection, specifically targeting the transition from the existing QCVN 09:2024/BGTVT standards. A significant focal point of this regulatory overhaul is the proposed mandatory integration of Acoustic Vehicle Alerting Systems (AVAS) for all electric and hybrid vehicles operating within the country. Under the current draft proposal, these vehicles would be required to emit an artificial warning sound when traveling at speeds below 20 km/h. The regulation aims to address the inherent silence of electric motors, which poses a substantial risk to vulnerable road users, including pedestrians, cyclists, and individuals with visual impairments.

The Rationale Behind the AVAS Mandate

The push for AVAS in Vietnam stems from a global consensus regarding the safety hazards posed by the "silent" nature of electric vehicles (EVs). Traditional internal combustion engine vehicles emit a distinct mechanical hum, vibration, and exhaust noise that serves as an auditory cue for pedestrians to judge the proximity and speed of an approaching vehicle. In contrast, EVs are nearly silent at low speeds, relying almost exclusively on tire-to-road friction and wind resistance, which are negligible at speeds under 20 to 30 km/h.

By introducing an artificial sound, the Vietnam Registry seeks to bridge this sensory gap. However, the proposal specifies that these sounds must not be confused with emergency sirens or common musical tones. The intent is to provide a consistent, recognizable warning that alerts pedestrians to the presence of a moving vehicle without contributing to the pervasive noise pollution already affecting major urban centers like Ho Chi Minh City and Hanoi.

Technical Implementation and Regulatory Nuance

The technical specifications under consideration suggest that AVAS units should be synchronized with vehicle movement. When a vehicle exceeds a certain speed threshold—typically between 20 and 30 km/h—the AVAS would automatically deactivate, as ambient tire and wind noise become sufficient to alert those in the vicinity. This automated switching mechanism is designed to prevent unnecessary noise in high-speed traffic environments, such as expressways.

Industry experts have noted that the integration of AVAS could be achieved through a dedicated speaker system linked to the vehicle’s onboard diagnostic (OBD) port. By pulling real-time speed data, the system can modulate the volume and pitch of the warning sound in correlation with the vehicle’s acceleration. This approach mimics the behavior of a mechanical engine, providing intuitive feedback to both the driver and the surrounding public.

Global Context and Regulatory Precedents

Vietnam’s proposal is not an isolated experiment but rather a alignment with established international safety standards. The United Nations Economic Commission for Europe (UNECE) has been a leader in this domain, with the R138 regulation providing the foundation for AVAS implementation globally. The 2025 update (version 02) to this regulation offers more rigorous and clearly defined parameters than its 2016 and 2017 predecessors, serving as the primary blueprint for the Vietnam Registry’s current initiative.

In the United States, the National Highway Traffic Safety Administration (NHTSA) implemented the Federal Motor Vehicle Safety Standard (FMVSS) 141 in September 2020. This mandate requires all new hybrid and electric vehicles to meet strict sound emission requirements to ensure they are audible to pedestrians. Similarly, Japan has been at the forefront of this safety movement since 2010, following advocacy from the Japan Federation of the Visually Impaired. Japan’s regulations became mandatory for new model hybrid and electric vehicles in March 2018 and were expanded to cover all such vehicles produced after 2020. China has also adopted similar standards, heavily influenced by the UN R138 framework but customized to account for the unique, high-decibel acoustic environment of its dense urban centers.

Expert Perspectives and Local Challenges

The proposal has drawn mixed reactions from automotive experts and urban planners in Vietnam, who acknowledge the safety benefits while highlighting the logistical challenges of implementation. Anh Vo Khoa, a prominent automotive sound expert based in Ho Chi Minh City, expressed reservations regarding the blanket application of such rules in Vietnam’s unique traffic landscape.

"While the safety of pedestrians is paramount, we must consider the reality of Vietnamese traffic," Khoa stated. "In cities like Ho Chi Minh, where traffic congestion is a constant, requiring every electric vehicle to emit a warning sound could lead to significant auditory pollution. Our road infrastructure is vastly different from that of Europe or the United States, where lanes are wide and traffic flows at higher speeds. Here, the density of motorbikes and the complexity of traffic flow require a more nuanced approach."

Khoa further suggested that if the regulation moves forward, the technical implementation must be highly sophisticated. "The system must be intelligent enough to discern between moving in traffic and being stationary in a jam. If the system is constantly emitting sound while a car is stuck in a gridlock, it will only increase the stress levels of road users and pedestrians."

Conversely, Dr. Nguyen Thanh Sa from the Ho Chi Minh City University of Transport and Communications emphasizes the necessity of the system for public safety. "AVAS acts as a crucial sensory bridge. It is not just about alerting pedestrians; it provides an added layer of situational awareness that helps the driver understand their own presence in the traffic flow. By adopting the UNECE R138 standards, Vietnam is ensuring that its automotive industry remains aligned with global safety protocols, which is vital as the country increases its production and import of electric vehicles."

Chronology of the Regulatory Development

The timeline for this initiative reflects a broader shift in Vietnam’s automotive policy:

• 2020-2022: Initial discussions within the Ministry of Transport regarding the rise of EVs and the lack of specific acoustic standards for low-speed maneuvering.
• 2024: The introduction of QCVN 09:2024/BGTVT, which set the stage for updated technical inspection requirements.
• Late 2025: The Vietnam Registry initiates the public comment phase for the proposed amendment to mandate AVAS, incorporating international standards like UN R138.
• 2026 and Beyond: Projected period for the finalization of regulations, potential phase-in periods for manufacturers, and the eventual mandatory installation on all newly registered electric vehicles.

Implications for the Vietnamese Automotive Market

The transition toward mandated AVAS will have clear implications for manufacturers and importers. Automotive companies will need to calibrate their onboard systems to comply with these specific auditory requirements before their vehicles can pass the national registry’s inspection. This may necessitate software updates or hardware additions for existing EV models sold in the country.

For the average consumer, this means that the electric vehicles of the near future will possess a distinct "identity" or sound signature. However, the regulatory focus remains on ensuring this signature is subtle enough to be unobtrusive while remaining effective enough to prevent accidents.

The Vietnam Registry’s proactive stance demonstrates an attempt to balance technological advancement with public welfare. By looking to established international precedents while acknowledging the local context of dense, mixed-mode traffic, the authorities hope to create a standard that improves safety without sacrificing the comfort of the urban environment.

As the consultation period continues, the focus will likely shift toward finding the "Goldilocks zone" of sound—a volume and frequency that satisfies safety inspectors, protects vulnerable pedestrians, and respects the acoustic limits of Vietnam’s bustling city streets. The final outcome of this proposal will likely serve as a benchmark for the region, signaling Vietnam’s commitment to modern, safe, and regulated electric mobility.