According to government statistics, 1 to 2 percent of all accidents in California and across the U.S. are caused by drowsy driving. However, researchers from the AAA Foundation for Traffic Safety conducted a study that suggests the numbers may be even higher.
There are currently several limitations in the assessment of drowsiness in drivers. For one, there is no accurate method that police officers can use to determine drowsiness, and drivers themselves may not be aware of the condition they're in. If they are drowsy, they might choose to keep it out of the police report. As government statistics are based on police reports and post-crash investigations, researchers say that their percentage is ultimately misleading.
The AAA study involved more than 3,500 drivers in different parts of the U.S. Over several months between October 2010 and December 2013, researchers monitored their driving through in-vehicle cameras and other equipment. They also measured drowsiness based on how long the drivers would close their eyes; this is known as the PERCLOS measurement.
After studying the 701 crashes that drivers were involved in, researchers concluded that 8.8 to 9.5 percent were related to drowsiness. Sleepiness contributed to over 10 percent of crashes that led to airbag deployment, injuries or property damage. Researchers additionally noted that drowsy driving was three times more common at night.
The difficulty of showing that a driver was drowsy should not deter victims from pursuing an accident claim. They may want to consult with an auto accident attorney to build up the case. What matters is showing that the defendant committed certain negligent actions leading to the accident; whether those actions were the result of drowsiness or distraction is secondary. The attorney may then be able to negotiate for a settlement out of court or litigate if negotiations fail.