If there is no road or part of a road specially designated for them, mopeds...

The driver of any animal-drawn vehicle, special vehicle with a maximum authorised weight not exceeding 3,500 kilograms, cycle, moped, cyclist-following vehicle or vehicle for persons with reduced mobility, where no road or part of a road is specially designated for them, shall travel on the right-hand hard shoulder, if it is passable and sufficient for each of them, and if it is not, shall use the minimum necessary part of the carriageway. Vehicles required to use the hard shoulder are prohibited from doing so side by side, except for bicycles, which may do so two abreast, keeping as close as possible to the right-hand edge of the road and forming a single file on sections with limited visibility or when they form traffic congestion. On motorways (autovías) they may only travel on the hard shoulder without encroaching on the carriageway under any circumstances. Mopeds may also travel two abreast on the hard shoulder, without encroaching on the carriageway under any circumstances. The driver of any of the vehicles required to use the hard shoulder, except bicycles, may not overtake another if the duration of travel with vehicles placed side by side exceeds 15 seconds or 200 metres of travel.