I did a few months ago, actually. It felt pretty good too!

I was responsible for traveling around the country to collect transportation information with a piece of shit van (kind of like the google car). Sounds cool, right? Not when you don't get to come home for over four months, get about one day off a week, and drive for nearly ten hours a day (unless it rained). Once I finally got a week off in between projects I was told I'd have to drive to the west coast and back in a few days to pick up and switch out another vehicle that another crew was using. SURPRISE!! I ended up having to stay while my partner and a person from the other crew got to go back. They didn't tell me this until I got there, yet they knew the whole time. I had only packed for a few days.

After working that surprise project for another month, I had just about reached my limit. The saving grace of my next (third) project was that it was about an hour away from my house. However, we had a different vehicle that was very old and sensitive. We would hit a bump in the road, the software would crash, and we'd lose all of the data we'd just collected. After constantly reporting this and our superiors doing nothing about it, my partner and I seriously considered quitting. Then it happened. They gave me a lot of shit for wanting a weekend off for a family gathering after a very stressful week. After that, my partner and I each called the office to tell them we were dropping the van off there. We both quit that day.

Although I probably should have given notice, I couldn't take it anymore. I did give them some feedback in an exit interview, however. My weekend was awesome, too!

EDIT I totally spaced out and forgot to mention all the safety issues that were problematic as well. Not only did they have us zip-tying loose brake cables, they also were not happy when we wanted to take our van in to get the COMPLETELY bald tires and grinding brakes replaced (not an exaggeration, I actually have a pretty sweet bald tire pic from the incident). Every time we would mention our concerns they would just tell us to tough it out because the project was almost over. Sorry, I don't feel like driving through the mountains on bald tires and bad brakes.