Are you freely permitted to use headlight flashes to warn other drivers in any situation?

Why this is the correct answer

Headlight flashes are not freely permitted for any kind of warning. Spanish traffic rules allow them only as a substitute for the horn and exclusively for three specific purposes: (1) to avoid a possible accident, especially on narrow roads with many curves; (2) to signal your intention to overtake, outside built-up areas; and (3) to alert other road users to your presence in certain regulated conditions. In all cases, you must also avoid dazzling others. Any other use of headlight flashes — such as warning about police checkpoints, greeting another driver, or pressuring a slower vehicle — is considered improper use of lighting and is punishable with a fine. Option B is incorrect because simply not dazzling is a necessary condition but not a sufficient one: the flash must also correspond to one of the specific regulated purposes listed above. The image shows a nighttime encounter with an oncoming vehicle — a clear example of a situation where improper use of flashes could cause dangerous dazzle.