Answer to Question # 2:

Much of the land along rail lines in any American city is filled with factories and other industrial facilities because industrial users needed the railroads to obtain raw materials and to ship finished products. In some cases these factories have been redeveloped for other uses but because the parcels are large they tend to attract uses like shopping centers that require large lots.

The land along the large grid streets, on the other hand, is usually filled with commercial buildings of various kinds, often large stores, particularly at the intersections.