I found a website about the new Hi-viz jacket law. it seems only two are required if my translation is correct.
http://www.thisfrenchlife.com/thisfrenc ... iangl.html
HOW MUCH IS IT NECESSARY SOME? In France, at least 1. But attention the rules can be different abroad (think of transborder displacements) WHICH MODEL? Its conformity is attested by marking EC. There are waistcoats with 2 or 3 bands autoréfléchissantes.
OUR COUNCIL Have at least 2 waistcoats inside the cockpit to equip the driver and a passenger in assistance. In the event of breakdown or of accident, or stop on the roadway of night like day ?? To light the hazard warning lights ?? to quickly cover the waistcoats before leaving the vehicle. Leave with dimensions passenger preferably. ?? To evacuate the vehicle and to put all the occupants at the shelter (not to remain on the roadway or the BEAM!) As from on July 1, 2008 are obligatory on board all vehicles fitted with body with engine whatever the category or use (VL - PL - VUL…) : Waistcoats of safety Warning triangle Waistcoat 2 bands Waistcoat 3 bands, more visible, especially if intervention on convey