It’s safe to say that we don’t know much about sleep. For all the studies that have been done, what we know about sleep can be summed up with just one phrase: We need it. All the rest of what we “know” is conjecture; a collection of quasi-educated guesses. Do we need 8 hours of sleep as some people say, or should we sleep in 3 hour REM cycle increments? Is it better to sleep for exactly the same amount of time every night, or should you only sleep as much as you feel you need for that particular night?
Before the Hours of Service rules were overhauled in 2005, drivers could take their rest in one block, or split up into multiple blocks as long as no period of rest was for less than 2 hours. This allowed drivers to pull over and rest when they felt tired rather than feeling pressured to keep driving for their full allowable time.
The HOS rules got an overhaul when the FMCSA saw studies which showed that drivers are less likely to be fatigued if they sleep for a single eight-hour block than if they break up their sleep into multiple shorter rests.
The results of a new study sponsored by the FMCSA hoping to discover the effect split sleep schedules have on driver safety have been published. Apparently, it doesn’t make a discernible difference if you sleep in one long chunk or if you break up your sleep into two shorter breaks.
It’s doubtful that split sleep schedules will be allowed again when the new HOS changes go into effect on July 1st, but this is definitely one more nail in the coffin of a dangerous bit of over-legislation. If drivers can operate just as safely on a split sleep schedule, why force them onto a schedule that puts them in greater danger?