yes, but actually this way you map each one anyway so its also a no 
but for what you mean its: yes 
take a look at the last screenshot.
the pillars i made as example for you are just cylinders.
unwrapping the uv (is like rolling the cylinder over gift wrap paper to seal it) results in
a rectangle with the same amount of faces planar on the uv sheet.
to make them share the same uv space you go e.g. in face selection mode, mark them and
put them on top of each other. then you can also mark them all and scale them.
dont be afraid to overlay your pillars uv’s with those of other parts of the bridge (or move the other
parts away for later) because you assigned them different ID’s in the prior step.
this way you need a multimaterial with 2 layers. one for the bridges main part texture and one texture
for the pillars. the layer 2 (or 2nd) texture would be the pillars texture.
if you want ONE texture for everything (a so called atlas texture) you would want no
overlappings of all the uv’s for each texture to achieve more variety in your texturing
process. the downside would be a lower texture resolution.
the next learning step after that would be to do normal baking.