I don't drive long distances (but I used to commute ~40 min to work before I moved). I work nightshift and dayshift (2 jobs). I've upgraded from just caffeine pills, and if I am driving (and not well rested) I have a nicotine lozenge in my mouth for 100% of the drive (I don't smoke. I started taking these to help stay awake.) Also your point on naps is key. Even with 2 stimulants (caffeine and nicotine) I have hit my limits and needed to pull over. But I almost never feel the urge to sleep with a lozenge in my mouth literally instantly inserting nicotine into my bloodstream over time for the entire duration of the drive (caffeine is delayed because it uses the digestive system, nicotine is not because it goes through your skin).

A couple of notes for anyone reading this: everyone's body is different. Some people can still have microsleeps, even with stimulants. Only sleep (or naps) can really 100% prevent it. Aaaaaand nicotine is addictive. Again, everyone's body is different. I can have 25+mg of nicotine and 1000+ mg of caffeine per day for a week (or month) straight and then quit cold turkey the next day because I have time off work and don't need to stay awake. Your body might get addicted for life. (For reference, a medium coffee is approx 100mg caffeine and a cigarette is approx 1 or 1.5mg nicotine). Also note: nicotine is actually poisonous, and large amounts of it without a tolerance to it can kill you (this is usually not possible because one of the first side effects is nausea, which would force you to stop.... But not always). And in my specific instance, caffeine actually has worse withdrawal (and is therefore more addictive) than nicotine. When I take no drugs cuz I'm off work and can't justify it, the caffeine might force me to take painkillers just to function (headaches and muscle pain so bad that I literally can't do anything). Also, yes, I'm probably at a heart attack risk. But it's better than being homeless (or dying in a car crash).