En una calzada con doble sentido de circulación y dos carriles, ¿por dónde debe circular un vehículo especial cuya Masa Máxima Autorizada (MMA) supera los 3.500 kg?

The correct answer is in the lane on its right. As a general rule, special vehicles with a MAM of more than 3,500 kg behave like a lorry or a car as regards their position on the road: they must drive on the carriageway, not on the hard shoulder. It is important to distinguish them from special vehicles of up to 3,500 kg, which must use the hard shoulder if there is one and it is usable. So: 1. They may not use the right-hand hard shoulder (reserved for light special vehicles, cycles, mopeds, etc.). 2. They may not use the left-hand lane, because on a two-way road with two lanes the left-hand lane is for traffic in the opposite direction (entering it would be very dangerous, except to overtake where this is allowed).