Within a locality, the rule for traveling on traffic lanes is not the same as that applied on motorways. Article 14 of the Road Code states that drivers must use the "traffic lane most convenient to their destination," which means there is no automatic obligation to leave the left lane simply because the right lane is free. The determining factor is whether the chosen lane is truly the most appropriate for the route the driver intends to take.
The relevant legal concept is "locality," not simply "city." The Road Code defines a locality as an area with buildings whose boundaries are marked by regulatory signs. Within these boundaries, the choice of lane must be related to the destination and to the maneuvers to be performed, such as changing direction, overtaking, stopping, or parking. Existing signage, such as arrows on the road surface and vertical signs, takes precedence over general traffic rules.
If another vehicle approaches from behind, the mere fact that someone is in the left lane does not, in itself, create an immediate obligation to move to the right, provided the lane is appropriate for the destination. However, the general duty to facilitate overtaking remains in effect, as set out in Article 39, which obliges the driver to move as far to the right as possible when no obstacle exists and not to increase speed during the overtaking maneuver.
Failure to comply with Article 14 carries a fine of between 60 and 300 euros. However, the offense does not result from the simple fact of traveling in the left lane with the right lane free, but rather from using a lane that is not convenient to the destination or from a lane change made outside the conditions provided for by law.
