The well-known Japanese physicist and essayist Torahiko Terada (1878–1935) said that a great natural disaster comes when people forget the last one. Railway accidents occurred more frequently when safety systems were underdeveloped. In the 1960s, Japan's economy was growing fast but the railways suffered from under investment, resulting in a series of serious accidents due to crammed train schedules and poor safety equipment. The number of accidents has decreased dramatically since then thanks to huge investment and tightened training to improve safety. But even today, with much more advanced technologies to cover technical faults and prevent human errors, accidents still occur before people have forgotten the last one.
Today's accidents are more complex than they used to be. When the railway system and technologies were simple, most accidents were attributed to human errors such as negligence and misconduct. Today, railways are operated as a systematized complex of advanced technologies and skilled workforce. Today's accidents are more often caused by factors such as mismatched technologies, inadequate man-machine interface, and lack of an overall view to combine different technologies and human factors. So long as the railway is a manmade system, there is no absolute safety in rail operation. Technical development has contributed to fewer accidents, so the railway should not hesitate to invest actively for improved safety, although this is often hugely expensive. However, even with the most advanced technologies, human error still plays a crucial role in accidents and the railway must try hard to improve human skills and attentiveness.