Typing the letter v to produce ü is pretty standard in most Pinyin-related software — the letter v not being used in Pinyin except for loan words, and the letter ü not being found on traditional qwerty keyboards.
Here’s an official sign not far from Tian’anmen Square in Beijing that provides an example of an unconverted v.
Of course there’s the usual word-parsing trouble as well, which can indeed be tricky in some cases (but not so much that everythingneedstobewrittensolidlikethis).
This should be “Zh?n? Qiáo d?ng héyán” (?????? / ?????? / Weaver Girl’s Bridge, east bank) or perhaps “Zhinü Qiao Dong Heyan” or “ZHINÜ QIAO DONG HEYAN”.
Some people might not think this is worth categorizing as a problem. My position, however, is that government has an obligation to write things properly on its official signage. (If this were on some ad hoc sign put up privately it would still be interesting but less problematic.) So, if anyone’s OK with the V, would you also be OK with, say, “??????”?
OTOH, as mistakes go, at least v remains distinct, unlike when ü gets incorrectly written as u, which is so common in Taiwan that I don’t recall ever having seen a ü on official signage. (Pinyin has the following distinct pairs: nü and nu, lü and lu; nüe (rare) and lüe are also used but not nue or lue since the latter two sounds are not used in modern standard Mandarin.