When, because of the speed at which they are traveling, they can be passed safely, and even if the line is solid, a passenger car may enter the lane of oncoming traffic to pass...

Correct answer: bicycles.

Where passing is prohibited, for example by a solid line, you may pass a bicycle using the oncoming lane if it is traveling slowly enough for you to pass safely and you first check that no one is coming. This exception does not include motorcycles or heavy vehicles, even if they are traveling slowly.

Reglamento General de Circulación · Reglamento General de Circulación