Greg, what I am saying is not that the HOS rules are exhaustive in their review of all sleep deprivation studies, but rather that their conclusion that a certain number of hours of sleep are needed for proper rejuvenation is persuasive. However, this conclusion does not mean that a driver is going to get that needed rest during a required rest period.
In other words, I think we can all agree that most people will function better with an uninterrupted eight hour period of sleep, but the question then is what is the best way of getting a driver to get that eight hours of sleep, and I think that merely forcing him to park his truck for eight hours is a terrible way of trying to get him to sleep. A much better way would be to design the rules so that he can stop and sleep for eight hours WHEN HE IS TIRED, whenever that may occur. Writing rules like this would be difficult and maybe impossible, but if the purpose of HOS rules is to prevent tired drivers, YOU MUST provide an incentive for them to rest WHEN THEY ARE TIRED.
Sorry if I am repeating myself.