Prospective drivers with a neck size greater than 17 inches or a body mass index, or BMI, of 35 or greater typically require screening for sleep apnea, according to CDL Labor Logistics. The Department of Transportation recognizes the two characteristics as key indicators of sleep apnea, which affects a driver's ability to drive safely.
Sleep apnea is a leading cause of excessive daytime sleepiness. The disorder causes pauses in breathing or shallow breaths during sleep. Since the disruption results in an overall poor quality of sleep, sufferers often feel tired during the day, as CDL Labor Logistics explains. A Federal Motor Carrier Safety Administration?s study found that an estimated 28 percent of those with a CDL suffer from mild, moderate or severe sleep apnea.
Department of Transportation medical examiners are ultimately responsible for ensuring that drivers are medically fit to operate commercial motor vehicles. As of 2015, examiners are unofficially required to test all drivers with a BMI over 35 or a neck size of 17 or greater for males and 16 or great for females for sleep apnea. However, employers may elect to impose stricter standards, as DOT Physical Doctors explains. Drivers who test positive for the disorder must then undergo successful treatment with a CPAP machine prior to obtaining Department of Transportation medical certification, according to SleepHealth.