Photomontage - Combining images
Photomontage is the assemblance of separate images to form one. The imagination is the limit of Photo-montage.
Where scale is involved as in this case, slight alterations to the bridge were needed to marry the two parts together, to ensure the busses were riding on the road.
Inserting object into to the scene requires thought about the light and shade within the main image. Colour and grain matching are performed to ensure a seamless result.
To see more great examples of photomontage art see my photoshop digital art portfolio on the blog