Improper and reckless behavior kill, not speed per se. Going the speed limit around a blind curve without sufficient stopping distance or going faster than one's headlights are dangerous. There is no universal rule except don't drive faster or riskier than your or your vehicle's capabilities or endanger others.
If you've ever driven in italy you know that velocity is normally measured in a 100km/h road, right after a 20km/h sign that was there for no other reason than to fine people. For bonus points the sign can be hidden behind a bush or can be so old and faded nobody knows what it says.
I was momentarily confused because where I live "Off Highway" has a specific legal meaning - meaning not on public roads, e.g. on dirt trails or in a farm field.
If the person in front of you has to brake hard or swerve to avoid an obstacle, your speed differential with them can very quickly become equal to your speed.
If there’s a stationary object on the road, your speed differential is always equal to your speed.
In many circumstances that cause deadly accidents, speed differential vs speed is just pedantry.
I don’t speed off highway. On highway though when traffic is light, visibility is good, I don’t see the big deal with going 70 in a 60. The detector gives me peace of mind so I can focus on what’s relevant rather than playing “find the cop” or, worse, going the speed limit and falling asleep. :)
