On roads with three carriageways, as a general rule, the side carriageways should be used:

Correct answer

In one direction only, without prejudice to the authorities being able to establish another direction, which will be duly signposted.

On roads with three carriageways, the central one may be intended for traffic in both directions or in one direction only, permanently or temporarily, as indicated by the relevant signs. The side carriageways, on the other hand, are intended for traffic in one direction only, without prejudice to traffic authorities being able to establish another direction of travel for the side carriageways or for one of the lanes, which must be appropriately signposted.