Yeah, road driver is linehaul. But just because you applied for the position doesn't mean you'll automatically start off on linehaul. Usually you'll start off on the docks, then P&D, and then linehail.
Usually at UPSF, you get trained in all divisions in the beginning , so that way on slow days, they'll put you on the docks or someplace else and you'll already know how to do the job. And yeah, linehaul is nighttime work.