When Taillights Start 'Talking': Can Blue Lights Become Standard Signals for Smart Driving?

When a car drives past you, besides braking and turning signals, its taillights can tell you another thing—it is driving autonomously. This isn't a sci-fi movie, but a pragmatic question left to the industry after the uncamouflaged driving posture of the Xiaomi Pengcheng SkyNomad N90 Max was exposed.

Conclusion first: The small blue light is likely to become a standardized human-machine interaction signal in the era of intelligent driving, but its true value depends on regulatory adaptation and ecosystem integration, not merely hardware stacking.

I. This Is Not Decoration, It's a Signal

From the news, the small blue light was initially developed by a third party, "Digital Corner," for the Xiaomi SU7/Ultra/YU7, and now appears on the factory test vehicle of the Pengcheng N90 Max. This isn't accidental. In a consultant's framework, this is a typical penetration path from "aftermarket to OEM," reflecting users' awakening demand for visualizing autonomous driving status.

The essence of car lights is a communication tool—not just between drivers, but a language between vehicles and pedestrians, and vehicles and vehicles. Traditional taillights tell others "I am decelerating" or "I am turning," but in autonomous driving states, the vehicle needs to tell the outside world "There is no human driver controlling me at this moment."

This is similar to the "Autopilot" indicator light on airplanes. When passengers see it lit, they know the pilot has temporarily let go, but the plane is still under precise control. In the automotive field, the small blue light is an extension of this logic.

II. Benchmarking Overseas: From Concept to Implementation

Mercedes-Benz EQS once showcased the concept of an "autonomous driving status light": when the vehicle is in Level 3+ autonomous mode, an external blue light strip stays lit, signaling pedestrians and other vehicles "I am in autonomous driving state." Waymo's Jaguar I-PACE fleet equips roof-mounted LiDAR arrays while using blue lights to indicate "driving autonomously."

But the issue is that overseas solutions either remain conceptual or require complex hardware support. The low cost of the small blue light (requiring only two LED beads and simple control logic) and its modifiability make it easier to popularize in mass-produced cars. This is precisely the strength of China's automotive supply chain: pushing a feature to market quickly through software-hardware decoupling.

III. Xiaomi's Ecosystem Chess Game

The Pengcheng N90 Max is an important link in Xiaomi's ecosystem chain. From phones to cars, and then to intelligent driving auxiliary lights, Xiaomi is building a "Person-Car-Home" full-scenario interaction system. The small blue light seems like a small accessory, but it could become a bridge connecting user perception with trust in autonomous driving.

[!example] Benchmarking the history of "breathing lights" in the mobile phone industry: Early phones used breathing lights of different colors to indicate unread messages, later replaced by screen notifications. But the logic of the small blue light is different—it faces the external environment, solving the safety pain point of "how other cars judge if I am driving autonomously," rather than just providing information prompts.

Looking at it through a SWOT analysis framework:

• Strengths: Low cost, easy to modify, can integrate with Xiaomi ecosystem (e.g., customizing light modes via phone App)
• Weaknesses: Currently no unified standard; light meanings may conflict across different car brands (e.g., red for warning, blue for autonomous driving, but blue might be mistaken at night)
• Opportunities: Chinese regulations for connected intelligent vehicles are advancing requirements for external prompts of autonomous driving status; the small blue light could be a preemptive solution for regulatory needs
• Threats: If regulations mandate specific colors or positions, aftermarket modification solutions might be replaced by OEM ones

IV. Pragmatic Challenges

However, it must be admitted that the small blue light is currently still in the "user-initiated stage." Lack of unified standards means blue lights on different models might represent different meanings: some indicate "autonomous driving activated," others might just mean "charging" or "welcome mode." This actually increases cognitive confusion.

Benchmarking overseas cases, the EU's R157 regulation has a preliminary framework for external prompts for autonomous vehicles, but discussions continue in the US and China. For the small blue light to become standard equipment, it requires:

1. Industry alliances (such as the China Association of Automobile Manufacturers) to push for defining a unified signal

2. Regulations clearly mandating vehicles display externally when in autonomous driving state

3. Car manufacturers incorporating light interfaces into design during pre-production stages (rather than relying solely on aftermarket)

V. Back to That Pengcheng N90 Max

From the photos, the small blue lights are installed on both sides of the rear, positioned low, separated from brake and turn signals. This design avoids conflicts with existing signal lights, but nighttime visibility may need real-world verification. As a new brand within Xiaomi's ecosystem, Pengcheng choosing to expose this detail before mass production looks more like a market probe: Are users willing to pay for "stability in autonomous driving"?

I'd rather leave an open question at the end: When the small blue light becomes standard, will we need a new "car light language" to handle different levels of autonomy—for example, flashing for Level 2, steady for Level 3, breathing for Level 4? This is not just a technical issue, but a topic in automotive sociology.

Original Link: https://www.ithome.com/0/977/205.htm