https://spanishtrafficlaw.es/section-ii-about-the-movement-of-vehicles/chapter-i-position-on-the-road/section-2-use-of-lanes/article-31-use-of-lanes-out-of-town-on-roads-with-more-than-one-lane-for-the-same-direction-of-travel/
Article 31 Use of lanes, out of town, on roads with more than one lane for the same direction of travel