1. It is forbidden to travel backwards, except in cases where it is not possible to go forward or change the direction of travel, and if this is done, this must be carried out in the shortest length possible (article 31.1 of the articulated text).
Remember that the only justification of a reverse manoeuvre is when there is no other possibility. There are cases of drivers who do not wish to turn around and so go several metres back with their vehicle to avoid doing any other manoeuvre, this action is not allowed. Reversing is only allowed when nothing else can be done.
2. The backwards route, as a complementary manoeuvre to stopping, must ensure that the parking or movement cannot be more than 15 metres or invade a crossroads.
3. The reversing manoeuvre on motorways is prohibited (article 31.3 of the articulated text).
4. Infringements of the rules of these requirements, when they comprise of the driver moving in the direction contrary to the stipulated route, will be taken very seriously, as foreseen in article 65.5.f) of the articulated text.