California is one of several states that is considering abolishing daylight saving time, and a recent study shows just why such a step can be beneficial. Researchers at the University of Colorado Boulder analyzed over 732,000 car crashes that occurred in the U.S. between 1996 and 2017 and found that every year, there was a consistent spike in fatal crashes in the initial week of the “spring forward” into DST.

Specifically, there was a 6% increase in fatal auto accidents, or 28 additional accidents nationwide that could have been prevented. The spike always followed after DST even, when the start of DST was officially pushed forward from April to March in 2007. Not only that, but residents on the westernmost edges of a given time zone see an increase of 8% in fatal crashes. Residents in these areas already tend to be sleep-deprived.

Lack of sleep is bad for health in general, so it makes sense how previous studies have said that every year, the first week of DST sees an increase in people suffering heart attacks and stroke. It can impair drivers in the same way that alcohol intoxication might: reducing attention, impairing risk assessment abilities and slowing down reaction times. Still, drivers can prepare for DST by, for example, getting to bed early for a few nights before the switch.

The study only covered fatal accidents, so the problem is undoubtedly worse. Many DST-related crashes can result in personal injury to innocent parties, in which case those parties may be able to seek compensation through a third-party insurance claim. Short of the defendant’s own testimony, there can be little to no proof of drowsiness, though, so victims may find it hard to establish a case. This is one reason why it might be wise to see a lawyer.