The UK speed tolerance has been tightened, you will now be booked if caught at any speed above the limit. That is not the point, though, the limit is an absolute maximum; you are obliged to drive at a safe speed for the road conditions. In the dark on a road that is badly lit and accessible to pedestrians that is perhaps 20mph. The risk of death to a pedestrian rises steeply between 30 and 40mph, so every mph counts. If you were to program autonomous vehicles to be safe, they would be limited to lower speeds than human ones. And would always give way. And in congested traffic, slowing all vehicles makes journey times less, because flow is restricted by junctions, not maximum speed. But try selling that to anyone.

To trip, as in fall over, is trebucher (like the catapult), but I would use debrancher, which is to disconnect or unplug.

Disconnected is "debranche" (that e at the end is e acute)

Actually, in France they say "Bon courage", much more appropriate. Courage in french means strength or determination.