I don't know why that would be something that would catch my eye, and from the pictures, the sign is clearly traffic related and its intent could then be instantaneously recognized.
Often times there are other traffic control devices or indicators that would make such prohibition more clear. (EDITED TO ADD: oops, didn't see CS's post)... None can be seen in your photos because of the angle looking upwards! Of course this makes the photos more difficult to authenticate (no street name signs or any other clear identifying features) for evidentiary purposes, and even *IF* it did hold such value, I still don't think it will get you much more that a fine reduction!

