The American Alley- a hidden resource. This Strong Towns article is just part one in a whole treasure trove of material about alleys as promising sites for incremental infill development.
"It is rare to find a street in America that does not seem to be almost wholly oriented around the movement of cars from one point to another. The street understood as part of the public realm seems to be forever lost, a thing of the past. There are political and cultural reasons for this, and a long history of how this came to be, well told by authors including Andres Duany (co-author of Suburban Nation), and James Kunstler (The Geography of Nowhere). Perhaps the most fundamental reason for this, though, is that most American streets—both historic and modern—are very wide, at least compared to streets of historic European towns and cities."