Honestly, when you drive, do you see someone that doesn't follow the safety guidelines? There are cases of corruption in the road. That mirror shows you an individual that doesn't keep the distance of security, so in any event, his vehicle could collision with yours. Is it your fault? Perhaps.
Cases of this kind should be taken much more seriously, because each year the number of fatalities and other accidents with severe injuries remains high. First, the police usually focuses speed, but there are similar methods to know if the security distance was appropriate or not.
Vehicles with cameras are very useful to have enough proof of those irresponsible individuals that play with others' life. With that data, you could —and you should— go to the police station to sue the owner of the vehicle.
Each signal is placed there for a reason, from the civil engineering sector. Please note that it's not for the believed capabilities of the driver or the vehicle. Too many reasons that try to bring every possible factor into account, with multiple eventualities. If a rare one appears, and the vehicle appears in the situation at a wrong speed or position, it would mean another accident. Fatalities could arise from pedestrians where children of course are included, drivers, passengers, wild fauna and as well property damage.
What's more lamentable is how speed doesn't create a life in itself. In a trip, going faster, the difference in time is not specially great, Two hours before? Half an hour? If a person loses too much time sleeping, perhaps it would be more interesting to subtract from here. The problem are those who never wake up after an accident. Take responsibility of any act before it's too late!