Si quiero incorporarme a la circulación efectuando marcha atrás, ¿qué precauciones debo tomar?

As a general rule, reversing is prohibited, except in the following cases, as an exception and always over the minimum distance necessary: 1. As a manoeuvre that complements stopping, parking or joining traffic. In this case, you may not reverse more than 15 metres or enter a junction. 2. When it is not possible to move forwards or to change direction or make a U-turn. In this case there is no limit on the reversing distance, and you may even enter a junction if necessary. Reversing is prohibited on dual carriageways (autovías) and motorways (autopistas).