cutting a line

My brother is a Surveyor. As in cutting lines through the backwoods of VA. No hacking through jungles. No, rather he has a desk job, now. And not Upton Sinclair, though he reads Upton, I'm sure. (most surveyors, don't, FYI, but he is smart). But sometimes he cuts the line. I think that's what they call it, when you go out and hack through the Kudzu, et al. You cut the line.

Sometimes I think I'm supposed to cut the line.