I think everyone in the scientific community would go along with the idea that circadian rhythms play a primary factor here, and if you're driving overnight, then you have more to worry about, and you have to manage that fatigue better, than if you're driving during the day.
Je pense que la communauté scientifique entière partagent l'idée que les rythmes circadiens sont un facteur important, et si vous conduisez de nuit, vous devez faire plus attention, et il vous faut mieux gérer la fatigue que si vous conduisiez de jour.