Guide rails, safety nets and bubble wrap are probably the main contributing factor of the general stupidity we see today. Everybody is constrained within these systems that make it so that the most minimal amount of brain power is required to adequately function within them. Lines of the road, stop signs, traffic lights, speed limits. Anybody is a brain on their shoulders can approach an intersection that does not have any sign or light, and navigate through it. Every time the power goes out this is evident.
Speed limits might be a necessary evil but 35 on a back road with no houses is ridiculous. 65 on a highway at 4 AM is unnecessary.
The point being, instead of people needing to actually consider "is my speed appropriate - is this intersection clear - am I too far left of center?" they simply live within the lines, rarely or never testing the boundaries except maybe for a quick rush in their youth.
This concept is everywhere in our society. Almost no thought is required to function. People live on muscle memory and reactions.
The road is not protected from local wildlife, and occasionally there might be another car in front going slower so realistically it's not possible to drive that fast for very long. The high speed train keeps a consistent 200mph and stops for nothing.