It should be flashing lights on all sides. If you brake suddenly, the acceleration sensor integrated in ESP/ESC (of course, the external sensor can also provide signals) will feel the acceleration. However, there is no obvious ity in the angle sensor of the car. Then it will be judged that you will brake sharply. At this time, the braking force will intervene in advance. At the same time, in order to ensure the safety of the front and rear cars, the double flash will be automatically turned on. About 10 years ago, this function has been added to the products of major suppliers.