I’m sure you’d be looking for an opportunity. I’m a lot less sure you’d be finding it. If he’s distracted or has dozed off, do you chance it? Just how confident are you that he won’t notice? Do you think he’s more likely to kill you if try to run, or if you cooperate?
Sure, but how much of a “semblance” does it need to be? He’s dozed off - do you think you can stop the car and get out before he wakes up and shoots you? Do you think you can detour to a highway patrol station and get there before he wakes up and shoots you? And just how confident are you that he’s asleep, and not just toying with you?
You stop for gas, and you have to get out to pump gas, and he turns away for a moment. How long is that moment? How confident are you that you can get way before he realizes you’re running and shoots you? And maybe a bunch of innocent bystanders? Or maybe he gets out to pump. Can you start the car up and get away before the pulls out his gun and shoots you? Or maybe he insists you both get out, and he’s right by you, watching the whole time, his hand near his gun.
I’ve had to stay awake for 48 hour straight before. And done complex tasks that required careful attention. It’s brutal. But it’s possible. It also impairs judgement and reaction time and the ability to think clearly. Which is another factor - those “semblances of an opportunity to escape” are going to get harder and harder to spot and take advantage of.