I agree absolutely with the scaled comment.

Lighting manufacturers work very hard to have light go ONLY where it is supposed to go, and as evenly as possible. Consider a streetlight for example: The idea is to light up the area under the fixture as completely and evenly as possible, but to have as little light as possible leaking to the sides where it might get into a window and annoy someone. Again, the Lightbeams program can give you a bit of insight into this, although it doesn't allow for simulations in an area larger than 20x20 feet. 

A street scene like this is actually taking IES to a rather extreme limit. In fact it is probably more effective for indoor lighting.