*Please note that many of these tips will make your driver angry. But rage is a good thing. It is better than caffeine at keeping a person alert.
Use music. The driver is entitled to whatever kind of music he wishes to listen to whether it is Lil Wayne, Merle Haggard, or even *gasp!* Celine Dion. Do not make fun of his music, just learn the songs and sing along with him. It helps to sing at the tops of your lungs in much the same way that David Spade and Chris Farley did in Tommy Boy.
Play games. No, I'm not talking about the sissy, kid games like "I Spy". We're talking serious, adult games that challenge your brain power. Questions like, "If you were the last man on Earth and had to pick one woman to repopulate the world with, who would it be?" You know, mature games like that.
Let's revisit tip #1 for just a moment. It helps later in the trip if you take one of those sing-a-long moments and discreetly record it using your cell phone. Later, if you catch him nodding off, start playing it. Tell him you're about to put it on YouTube. Remember what I said about anger earlier.
Randomly scream for no reason. Not a short kiddy scream but one of those "I'm being attacked by a rabid chipmunk" type screams. It doesn't have to be on a set pattern, maybe once every hour or so. This will wake him up. And if he asks you why you screamed, simply say, "I don't know what you're talking about."
Belching contest. Need I say more?
Get into a political and/or religious debate with him. Regardless how you feel on a certain subject, insist that everything he says is wrong, even if it's something that contradicts what you said earlier. Confusion + Anger = Awake for Hours
At various times throughout the trip, insist that either his directions are off or the GPS isn't working right. There's nothing like thinking you're lost to make you alert.
Ask him about various things in his life, even if you have no interest in learning about them. Getting him talking about himself will help keep him awake. However, here's a warning; this might put YOU to sleep.
Play the punch buggy game and hit HARD. Nothing like internal bleeding to keep you awake.
And finally #10
If he's still trying to nod off after all this and still won't let you drive, call up his wife/fiance/girlfriend (or his Mom if he isn't attached) and tattle on him.
Peace and Happy (Safe) Travels,