Several years ago I had a neighbor who worked odd hours. Sometimes she’d work in the day, sometimes leave for work at 4pm, and sometimes she’d be in her office for more than 24hrs. Our kitchen and dining room looked out onto her driveway and front door so we frequently saw her coming and going.
And thank goodness we could see her! Several times she pulled into her drive in the morning after being gone all night, and fell asleep right there in the car, with her head on the steering wheel and the engine running. We’d go and wake her when we noticed that the engine wasn’t turned off.
This is just one example of the dangers of drowsy driving. What would have happened if she’d fallen asleep on the road, or if nobody had been there to wake her up?