The dirt maps were sampled from Total Textures V5:R2 – Dirt & Graffiti
DVD tinted brown and then set to Multiply at various opacities, whilst the remaining textures were color-corrected once assembled.
The other rather obvious area visible to the camera is the actual street surface itself. As opposed to being unwrapped I used a composite map, which is a favored technique of mine. This allows you to alter the coordinates and blending modes of various textures to build up a surface and localize details such as dirt and wear.
Fig.03 shows the material on the left and the composite map, which is assigned at the diffuse level.
The road surface uses a single map (2), which is tiled by a value of 2.0 in both directions, whilst the dirt maps along the edges have been tiled and offset to attain the right position and scale in the scene. These also incorporate a mask to control the opacity, which is applied on the right of the layer (1).
There is a tiling issue along the street which could have been reduced by adding a new layer and an appropriate blending mode. but in this case I ignored it as it wasn't too noticeable.
The other component that takes advantage of unwrapping is the right-hand tower, which incorporates a single texture from the Total Textures V08:R2 – Vehicles
Fig.04 shows a detail of the tower, which comprises of some loose paneling surrounding an inner section that has been exposed and consequently rusted.
Fig.05 shows the texture and the corresponding map on the lower right, which has been tiled and color corrected. I used panel05 from Total Textures V08:R2 – Vehicles
to block in the tower.