A previous post here talked about how many truckers who drive around or just pass through Orange County, California, are required under the law to, from time to time, pull off of the road for a few hours and take a rest. The idea behind these rules is to make sure drivers get the sleep they need so that they don't experience truck driver fatigue.
A fatigued driver, after all, is very dangerous even if the driver manages to stay awake. Someone who is too tired can easily lose focus on the road and may not respond promptly to changes like a car that slows down suddenly. However, some truckers in California, particularly those who suffer from a condition called "sleep apnea," may experience fatigue even if they think they had enough rest.
Sleep apnea causes a person to stop breathing for short intervals while they are asleep, sometimes with a frequency that is frankly quite alarming. Among other things, this stop-and-start breathing means the person gets poor sleep, meaning the person will likely be very tired at all hours of the day, even if the person had eight hours the previous night.
If truckers do not realize that they have sleep apnea, which actually happens somewhat often, then the quality of their driving will likely suffer. As is the case with drivers who just have not gotten enough rest, they will be prone to dozing off behind the wheel. Moreover, they will have a hard time paying attention to the road.
Undiagnosed sleep apnea can obviously lead to serious and even fatal truck accidents. Even with a medical condition, a trucker is responsible for staying awake and alert behind the wheel. They must get treatment for sleep apnea if they need it. If they fail to do so and cause an accident, they may be financially responsible.