> It isn’t symmetric. Being X kph faster than traffic is significantly more risky than being X kph slower than traffic. You're neglecting one very important fa

> It isn’t symmetric. Being X kph faster than traffic is significantly more risky than being X kph slower than traffic. You're neglecting one very important fact: A driver who is correctly taking advantages of the freedom of a derestricted section, following all the rules and driving fast "the right way" doesn't interfere with other traffic at all. Likewise for a driver who is driving in the same manner on equivalent roads in other parts of the world that don't respect their drivers in the same way. If you're driving fast the right way, you don't interfere with anyone else. Compare that to a driver going significantly slower than the normal flow of traffic. That driver is always interfering with other traffic. Everyone wanting to drive the normal speed has to maneuver around them which creates problems for the next lane or two over. Depending on how easy it is to get around the slow driver they may also create road rage. Now, obviously if you screw up while driving fast the consequences are generally going to be substantially more severe, but slow drivers cause problems of their own just by being there, no matter how well they're driving otherwise. There's a reason most controlled-access highways require that your vehicle have a minimum level of power and some even have minimum speed limits. When the flow of traffic is X, a vehicle moving X-20 is a dangerous obstruction.