I too break the run into segments and yes it helps...Regular stops even if your not tired helps..A quick walk around the truck and exercise when you can..Keep yourself active while driving, little exercises,,checking everything every few seconds..and singing does help a great deal.. But nothing beats a great day of sleep..A weekly sleep schedule makes a hug difference..Make a plan that works for you and stick to it..If you start the week tired you will never catch up...Laying down and getting up at the same time everyday,,even if your tired,, stay up until your set time to sleep...A healthy diet and vitamin supplements....Coffee and energy drinks may help at the moment but will hinder your sleep as the stick with you longer then you think..
p.s. Scanners are illegal in commercial trucks in many states..