But you get to deal with the drunks, falling asleep drivers, night construction, animals, and roads that aren't plowed nearly as much as during the day.. if you're in the snowbelt.
Additionally, if you can make your body swing to the other side of the clock, it's a good gig. However, the 2am-4am circadian rhythm sleep cycle does really suck.. even when you are used to it.
I ran a overnight shuttle for a different company way back when and even though I had my body mostly switched over, it was still tough during that time frame. I'd do it again though if the pay was similar/better than FDX.