ROW is a pretty popular term used for "Right of Way" in which a city, municipality, town, agency, and on and on marks their territory. It's likely an I.D. tag for something (like a telephone pole) with a code on it for registering in their system. As a side note, our entire county in central Illinois is riddled with concrete posts that stick up about a foot above the ground that go deep in the ground (several feet of rebar) along the streets that say R.O.W. It's the "line" where your front yard becomes the city's responsibility (i.e. grading the ditch). Do you think I could turn in a mowing bill for the past 30 years since they will never come out and do that? Hmm...