Minor blunders, careless mistakes, and mishearing are part of everyone's daily life. This means that any driver can cause a traffic accident. And it is true that small errors sometimes lead to major tragedies.
But do all drivers run an equal risk of causing accidents?
We investigated this question by comparing the risk of licensed male drivers who have had accidents during the three-year period from 2001 to 2003 and those who have not had any during the same period. Fig. 1 represents the percentage of drivers in each category who had accidents during the following three-year period (2004-2006).
The chart shows that 16.7% of the drivers who had two accidents or more during the 2001-2003 period also caused accidents during the following three-year period, a significantly higher percentage compared with those who had had no accidents or only one accident during the earlier period.
Since accidents are rare occurrences, having one only once in three years can be attributed to pure chance.
But having accidents twice or more is likely to be due to factors other than mere coincidence.
There is apparently a statistically significant difference in the number of accidents during the 2004-2006 period between the group of drivers who had had only one accident during the preceding three-year period and the group of those who had caused two accidents or more. In other words, drivers who repeatedly caused accidents during a certain period are likely to have more accidents thereafter.
The statistically significant difference between the two groups indicates that not everyone is exposed to the same possibility of meeting accidents, but that some drivers are more prone to accidents than others.
Fig. 2 likewise compares the number of traffic violations during the 2001-2003 period and the number of traffic accidents in the following three-year period (2004-2006). Only 2.1% of the drivers who had had no traffic violations during the former three-year period had accidents in the latter period, whereas 7.9% of those who had committed five violations or more during the former period caused accidents during the latter. Apparently, the more traffic violations a driver commits, the higher the risk of his causing accidents.
|
