Spanish motorists are very aggressive drivers. Use the left fast lane on motorways only if you are going fast or overtaking another car. Otherwise, use the right or middle lane.

In Spain, the "fast lane" is the left-most lane on dual carriageways and motorways (autopistas and autovías). Spanish driving law is very strict regarding lane discipline: you are legally required to drive in the right-most lane whenever it is free. The middle and left lanes are strictly for overtaking slower vehicles. Once you have completed an overtake, you must signal and return to the right lane as soon as it is safe to do so. In 2026, Spanish traffic authorities (DGT) frequently use overhead cameras and drones to fine drivers for "middle-lane hogging," which can result in a fine of €200. There is no "slow lane" per se; the right lane is the "normal" lane. It is also important to note that undertaking (passing a vehicle on its right) is strictly prohibited and considered a serious traffic violation. On a three-lane highway, the far-left lane is reserved for the fastest-moving traffic that is actively overtaking others, but it should never be used as a permanent cruising lane regardless of your speed.