When should a driver use vehicle side lights?

Vehicle side lights are designed to increase the visibility of a parked vehicle, particularly in conditions of low light, such as on an unlit road. When a driver parks on an unlit road, using side lights helps other road users, including pedestrians and other vehicles, to see the parked vehicle more easily, reducing the risk of accidents. This is especially important in rural or poorly lit areas where the absence of streetlights makes it difficult for others to notice stationary vehicles.

While there are other scenarios where vehicle lights might be used, they do not specifically pertain to the purpose of side lights in the same way. For instance, using them while driving in heavy traffic or during daytime does not provide as essential a function as they do when a vehicle is stationary in low-light conditions. Using them during bad weather is typically more relevant to dipped headlights, as they provide better illumination and visibility under those conditions.