As you are probably acutely aware by now, daylight saving time began again for 2020 over the weekend. The custom is to set the clocks an hour ahead so that sunset occurs an hour later than it would otherwise. Daylight saving time ends in November when the custom is to set the clocks back an hour. 

You may be one of the people who appreciate the extra hour of sunlight in the evening, or you may be one of many people who feel frustrated over the loss of an hour of sleep. However, you may not be aware of how daylight saving time affects your risk of involvement in a motor vehicle accident. 

Safety impacts 

Science Daily cites a study by the University of Colorado Boulder into the effects of daylight saving time on drivers. The research took place over the course of two decades and looked at 732,000 motor vehicle accidents. Analysis of the data indicated that the risk of a fatal car accident increases by 6% in the week following the switch. 

Originally, daylight saving time took place in April, during which researchers saw a characteristic spike in motor vehicle accidents. They observed the same spike in March starting in 2007 when daylight saving time started occurring a month earlier. The study controlled for other possible causes of car crashes, including the day of the week, season and year. 

Reverse pattern 

The study shows a commensurate decrease in the number of motor vehicle accidents during the week after daylight saving time ends. The pattern seems to relate to a disruption of sleep patterns and affects those on the western edge of their time zone more than those in the east. 

There is no requirement for states to participate in daylight saving time. State legislatures in California, Florida, Oregon and Washington are considering joining the handful of states who already refuse to observe it.