For the crossing I was back on google maps to get my reference, back in Chicago. I found that it varies depending on where you go and generally there are around 6 to 9 slabs in rows of 2 or 3 at the crossing. I decided to make mine 3 x 3 as this fit well with my already made slabs mesh so I though it would be best to reuse it.
I began with a basemesh in 3ds max.
Continued it in zbrush for all the cracks and details.
The final texture process was not too difficult as I baked an ambient occlusion so this helped with my diffuse map, and I reused my moss texture from the slabs and broke it up using custom brushes. There will be no need to design a shorter curb as I can take the one I already have and let it sink into the ground to create the same effect.