Antes de cambiar de carril, ¿cómo debe avisar?

Warnings must be given clearly, well before the manoeuvre starts, and, as a general rule, using the vehicle's lights or, if that is not possible, the arm. Warnings given with the vehicle's lights must stay on until the manoeuvre they announce is finished. If the driver's arm signal and the vehicle's light signal contradict each other, we must follow what the driver shows, because the lights may be faulty. Brake lights are used to show drivers behind us that the vehicle is braking or that we want to reduce speed considerably. Sound signals, that is the horn, may be used to avoid accidents, when on an emergency call, and on narrow roads with many bends, both on urban and non-urban roads. The horn can also be used to warn that you are overtaking, but only on roads outside built-up areas.