I created a sidewalk for a street scene. I applied a high resolution (2500 x 2500) photo of concrete as a file texture. I tried both normal and projection and could get the texure to look ok either way.

When I first applied the texture it seemed way out of scale, much too large. The only way I have found so far to make the texture appear in what looks like a correct scale to me is to scale up the UV Texture map. When I do this the texture appears correct. However, the UV map is so large that it is not only outside the 0-1 area it is completely outside the entire texture area.

This doesn’t seem right to me. Is this the wrong way to go about this? Will this cause problems as the scene becomes more complex?
Is there a setting or another method that should be used?

I would recommend applying the texture without a projection and then use the 2D texture node that is created and up the Repeat U value
(or Repeat V if your texture goes the other way) till you get something that looks right.
This will have the same effect as streatching the UVs out past the 1 0 bounds.
Hopefully this helps.
~Ben