It's never too late to mend.

That saying should be kept in mind in the aftermath of a fatal crash involving a double-deck sleeper bus that claimed 36 lives on Sunday.

Besides looking into why traffic rules were violated so easily in the case, investigators and experts also need to find out what other hazards threaten passengers on these types of buses. At least six road accidents involving sleeper buses have taken place in the past 17 months, claiming 140 lives, according to statistics.

More than 30,000 of the buses are now operating in China, making up 1 percent of all passenger buses in the country. Even so, accidents in which the vehicles are involved cause 10 percent of all deaths in passenger bus accidents.

What makes the vehicles so dangerous? For one, they are tall and can easily turn on their sides. Inside, their aisles tend to be narrow, making it difficult for passengers to escape in an accident, according to reports. Even worse, most of their windows do not open and the quilts and blankets that are often stored on them easily catch fire.

Given the fact that these buses are frequently in fatal accidents, it is high time that experts took a close look at their safety.

A sleeper bus tends to be relatively cheap and convenient, thus giving low-income residents an alternative to speed trains and airlines. For that reason, the vehicles have played an important role in relieving the pressure the transport system is occasionally brought under, especially at times when large numbers of people are traveling for business or other purposes.

Banning sleeper buses, then, would only cause inconveniences for travelers.

Rather than that, experts need to devise measures that will make the vehicles safer and easier to evacuate in emergencies.

Toward the same end, traffic rules should be strictly enforced. The law, for example, requires drivers to either take a break after driving for two or three hours or, in the same situation, to have another driver take their place behind the wheel. They also must keep their speed within a certain range when road conditions are not good.

Last but not least, transport companies must always keep safety in mind. That, perhaps more than anything, will make accidents less likely to occur.