Some points of critic:
1. Don't use Times New Roman for signs. EVER! Use Roadgeek 2005 Series E instead.
2. The US-styled distance sign looks wrong. First, it never says "distance to:" and second, you can leave "miles" for the distances, since it would be obvious to use miles here.
3. Downward arrows on a ground sign style B doesn't look right. This sign should be overhang, or have only one arrow pointing to the top-left and one pointing to the top.
4. The sign models themselves look very unrealistic. Try to add more diagonal crossbeams, like the signs on Riiga's pictures.
5. A black symbol on a blue background is not clearly visible. Make that train symbol negative. White on blue has a greater contrast and it's better visible.
6. The fork sign (ground sign style A) looks just ugly, because of the dimension of some components. The text 500 ft. could be a lot smaller and placed at the bottom. Second, the arrow pointing to the right could be placed a lot lower, so the targets don't look compressed at the top of the sign.
7. The portal sign (UC Standard RHW
-6S Sign Gantry): are the arrows located above the correct lanes?