When should a driver use vehicle side lights?

Using vehicle side lights while parking on an unlit road is essential for ensuring visibility and safety. Side lights, also known as parking lights, help illuminate the vehicle's outline and make it more visible to other road users, especially in low-light conditions. This is particularly important when the vehicle is stationary in a place where it may not be easily seen, such as an unlit road. Properly using side lights in this context helps prevent accidents by alerting other drivers to the presence of your vehicle, thus enhancing safety for both the parked vehicle and passing motorists.

In other scenarios, while there may be specific circumstances where other options might seem appropriate, they do not explicitly necessitate the use of side lights in the same safety-focused context as parking on an unlit road. For instance, side lights are not typically required during daytime driving when visibility is generally good, and while they can be helpful in bad weather, the primary lights (dipped or full beam) are often recommended. Furthermore, using side lights in heavy traffic doesn't directly address the need for improved visibility of a stationary vehicle, which is the crucial factor when parked in the dark.