Energy boost to avoid accidents

I can remember afternoons when I felt so tired and I had to fight to stay awake while I was driving home. Yes, that is dangerous, and once I did hit a parked car because I momentarily blanked out while pulling away from a green light. So fortunately nobody was hurt. I didn't even get a ticket, though I guess my insurance company put it down on my driving record. It did scare me, so I now I make sure I get some sort of energy boost to make sure I have at least enough vigor to stay awake on the way home. Once I'm home it's ok to take a nap and sometimes I do, though often it's after I've been working at the computer for a few hours.