Scientists from the UK analyzed data for a decade. It turned out that there are fewer serious traffic accidents during the transition to daylight saving time.
A study by the University of Surrey showed a sharp a 15-20% reduction in the number of serious traffic accidents after the transition to daylight saving time. This decrease is due to fewer accidents occurring between 6:00 pm and 9:00 pm, as drivers had an hour more sunlight.
Similarly, the team also found that switching to daylight saving time in the fall increases the number of small traffic accidents by 13%. This is mainly due to smaller accidents occurring during the evening hours between 15:00 and 18:00, when an hour of sunshine is redistributed back into the morning. These results support the hypothesis that drivers are more sensitive to road lighting conditions than to possible sleep deprivation caused by daylight saving time.