To drive safely on a stretch of road with many curves, it is important to consider the proper use of lights, especially in **fog** conditions. Fog reduces visibility and makes the road more slippery, so it is recommended to turn on the **fog lights** to improve visibility.

- On roads with **dangerous curves**, it is crucial to exercise additional caution. The "dangerous curves" signage indicates that the stretch may present more difficulties for the driver.

- The regulations allow the use of front fog lights on roads with a **width equal to or less than 6.50 meters**. This is because on narrower roads, visibility and space to maneuver are more limited, increasing the risk of accidents.

- Additionally, in foggy conditions, one should drive slowly, maintain an adequate safety distance, and pay attention to road signs and markings.

Therefore, on a stretch of road with many curves marked with "dangerous curves," it is correct to use the front fog light when the roadway has a width equal to or less than 6.50 meters, as this improves safety when driving in reduced visibility conditions.