Zip merge Merge in turn

The principle of the "zip merge" (or "merge in turn") system is an integral part of the Road traffic regulations (Code de la route).

This principle applies on a carriageway with several lanes of traffic in one direction when, due to the closure of one of the lanes, traffic is slowed down to a greater or lesser extent. It means that drivers travelling in the lane that is closing do not change to the lane that remains open until the last moment, as the closure approaches.

Such a situation may arise, for example, in the context of a roadworks site or at a narrowing of the carriageway.

Drivers in the lane that remains open must make it easier for drivers in the lane that is coming to an end to change lanes, so that the latter can enter the open lane on an alternating basis: each driver gives way to a driver who is changing lanes.

Failure to comply with this rule is punishable by a warning fine of 74 euros.