At closed circuit tracks you may find they segment drivers or vehicles based on average and top speeds. But why would that matter when even the slow guys are going >100mph down the straight, and everyone there has opted into driving in such an environment? Because speed variance is the real danger.
A car driving down a country road with a 50mph speed limit is going 2-5x faster than a cyclist depending on the slope. And there's no shoulder or bike lane in the countryside so they have to block the lane. Coming over a blind hill even below the speed limit may not leave the driver enough time and distance to come to a full stop. If the oncoming lane has traffic in it there's not even an escape path.
I grew up biking and I love it, but I also grew up and recognize the dangers and how being a cyclist on a fast road is imposing your risk onto others. It's sociopathic to believe a driver who hit a cyclist feels no remorse, but some people seem to prefer martyrdom over adjusting their preferences a little, like picking up mountain biking or going to the velodrome. I liked riding around on 2 wheels so much and I didn't want to compromise on where I could go so I pulled my pants up and learned how to ride motorcycles. Now I can go anywhere I want on something that keeps me outside of the cage and gives me more power and agility than any car.
edit: perspective of a bike fanatic (I have 7 bicycles/scooters/motorcycles in my garage) living in the self-proclaimed "Bicycling Capital of the Northwest," where there's an astonishing 2 paved bike paths that are so swarmed with pedestrians as to be unrideable