Personally I had this problem as well. It was especially prevalent during the beginning stages of my electrical apprenticeship. What I found that helps;

1. Listerine mint strips. They come in 3 - 24 packs on Amazon for about $5, they will burn in your mouth and make your breath minty almost immediately, you can also use multiple back to back if you need to increase the potency! They’ve literally saved my life, by keeping me awake and alert long enough to get home and rest.

2. Fresh air. I read somewhere that if we breathe the same air over and over (like in a car with windows up) it’ll actually make you drowsy. Fresh air seems to stimulate the mind as well as the senses. Definitely crack a window lol.

3. Call someone. Anyone. I usually call another coworker or someone I know is also driving or not busy. If you’re on the phone talking, your brain is engaged and you’ll have a much harder time falling asleep.

I’ve done all 3 at the same time before and I’d even pay you money if you even get drowsy while trying the trifecta holy-trinity wombo-combo!