A second trial allowing motorcyclists to filter between lanes of slow-moving traffic is to be marked with new signs.
The trial, in 21 departments, will last three years and follows a smaller-scale five-year trial which ended in January with inconclusive results. The first trial did not involve new signs.
Filtering is widely practised and tolerated, but it is not officially in the Highway Code.
The trials aim to see if it can be introduced safely within a framework of rules.
Importantly, this would allow the practice to be taught to motorbike learners.
New signs will include a main sign.
Another sign which may be seen on relevant roads will be a red circular 50kph speed limit sign with a small panel under it showing a motorbike with the wording en inter-files (filtering) and another saying rappel (reminder).
The trial is on motorways and dual carriageways with a central reservation where the speed limit is at least 70kph.
Filtering is permitted by two and three-wheelers (less than 1m wide) in congested, stationary or slow-moving traffic if riders do not exceed 50kph and go no more than 30kph faster than surrounding traffic (30kph maximum if traffic is not moving).
They should use the lane between traffic furthest to the left and should not overtake any other two-wheelers also filtering.
The trial covers: Bouches-du- Rhône, Var, Haute-Garonne, Gironde, Loire-Atlantique, Hérault, Isère, Nord, Rhône, Alpes-Maritimes, Drôme, Vaucluse, Pyrénées-Orientales and all of Ile-de-France.