In short, all else being equal, the safest speed to drive is as close to the median speed as you can estimate. The probably of an accident increases with the number of cars that you pass and the number of cars that pass you.
If course it’s not completely cut-and-dry like that, and is more applicable to higher traffic situations, but it’s a good general rule.
It’s entirely about your safety:
https://en.wikipedia.org/wiki/Solomon_curve
In short, all else being equal, the safest speed to drive is as close to the median speed as you can estimate. The probably of an accident increases with the number of cars that you pass and the number of cars that pass you.
If course it’s not completely cut-and-dry like that, and is more applicable to higher traffic situations, but it’s a good general rule.