This passage is mainly about（）

A．the severity of the motor vehicle accidents
B．the responsibilities of the cyclists
C．the street walkers’ responsibility for the motor vehicle accidents
D．responsibilities of drivers and others’ for the motor vehicle accidents

The motor vehicle has killed and disabled more people in its brief history than any bomb or weapon ever invented. Much of the blood on the street flows essentially from impolite behavior of drivers Who refuse to respect the legal and moral rights of others. So the killing on the road may be regarded as a social problem.

In fact the enemies of society on wheels are a rather harmless people, just ordinary people acting carelessly, you might say. But it is a principle both of law and common morality (道德) that carelessness is no excuse when one’s actions could bring death or damage to others.

Researchers have estimated that as many as 80 percent of all automobile accidents result from the psychological condition of the driver. Emotional upsets can damage drivers’ reactions, slow their judgment, and blind them to ers that might otherwise be obvious. The experts warn that it is essential for every driver to make a conscious effort to, keep one’s emotions under control.

Yet the irresponsibility that accounts for much of the problem is not confined to drivers. Street walkers regularly violate traffic regulations. They are at fault in most vehicle walker accidents. Many cyclists even believe that they are not subject to the basic rules of the road.