It might be helpful to know that the French introduce Laws often in a knee jerk reaction without reflection of consequences in any way.
Law concerning hi-viz vests for car/lorry drivers were passed after a noticable increase of break-down personel and police were run over at the scene of an incident. It's worth noting that they rarely block the circulation on, say, an Autoroute but let the vehicles pass. That still hasn't changed much.
The need to carry breathalysers was supposedly limited to one in case the driver felt the need to test him/her self. The problem arose that a driver would need to carry TWO, assuming one was 'used' as you still have to have one at hand incase of a police check. The most silly aspect was that any breathalyser carried by the public had no standing as proof of drunk driving or not and the police would still use their own properly calibrated equipment anyway so the need to carry one one-used was simply unnecessary! In the end the companies who had set up to produce the gadgets, and they couldn't make enough quick enough, had no client base when the government froze the Law. It is still Law but is not pursued.
There was an ecology tax imposed on movement of heavy goods accross the country tracked by technical equipment mounted on gantries over the dual carriageways and Autoroutes. That met with destructive reaction by many, very much here in Brittany, with gantries being burnt and put out of use. The government backed down and pulled the plug but a whole industry was shelved leaving a void in lots of companies who had been set up to monitor and collect taxes from transport firms etc. let alone the money wasted on the gantries and on going maintenance.
Just some of the examples.