You need discipline to avoid inattentive driving more than advanced technology. You know roughly when you will get tired from driving: plan around that. Technology won't save you from poor judgement.

I do agree, power-naps are amazing to help you regain focus. One time I was driving and it was almost dawn, and I was desperately trying to force myself to reach the next town so I could get a room. I realized I probably wouldn't even make it that far and pulled over at the next rest stop and slept for 30 minutes. I woke up feeling more well-rested than I had any right to be.

When you start having micro-sleep episodes (your attention/memory has inexplicable gaps), or start experiencing sensory hallucinations, it's well past the time for you to rest.