At least one embodiment of this disclosure includes a method for an autonomous vehicle (e.g., a fully autonomous or semi-autonomous vehicle) to communicate with external observers. The method includes: receiving a task at the autonomous vehicle; collecting data that characterizes a surrounding environment of the autonomous vehicle from a sensor coupled to the autonomous vehicle; determining an intended course of action for the autonomous vehicle to undertake based on the task and the collected data; and conveying a human understandable output via an output device, the human understandable output expressly or implicitly indicating the intended course of action to an external observer.

Disclosed are an intelligent warning method, an intelligent warning system, and an intelligent taillight device based on motor vehicle taillights. The method includes: monitoring, in real-time, a current speed of a motor vehicle, a speed of a leading vehicle, and a speed of a following vehicle, and providing feedback to a preset main control module; acquiring, through the main control module, a real-time distance between the motor vehicle and the following vehicle to obtain a following vehicle distance, and a real-time distance between the motor vehicle and the leading vehicle to obtain and a leading vehicle distance; controlling, by the main control module, a first projection module integrated in the motor vehicle taillight and a second projection module installed at a rear of the motor vehicle to project on a road surface in response to that a preset projection condition is met.