Alley insertions

New Urban News Technical Page by Andres Duany, Michael Morrissey, and Patrick Pinnell

The alley offset, described in the last Technical Page, is a way of modifying alignment of alleys from one block to the next. It is used where baroque excess in vehicle size and speed would otherwise result in corrosion of the alley system’s multiuse flexibility. A similar effect may be gained by varying adjacent block alley types — changing from a C pattern, to an H pattern, a T pattern and so on. While even more effective in slowing vehicles, this tactic has disadvantages for the continuity of underground utilities.

But to think of alley patterns as susceptible only to such remedial adjustments is to miss a larger truth. Alleys are one of the great, complex, support technologies of civilized life. Beginning as mere backyard drainage ditches, they have evolved as the increase of societal wealth produced more intensity and variety of vehicular uses, delivery and haulage services, and utilities. The rise of alley use and the refinement of alley design parameters paralleled an increasing sophistication in segregation of noxious uses in increasingly dense towns and cities. It must also be noted, as regrettable historical fact, that certain human beings were considered less desirable members of society and therefore “logically” were quartered amongst the noxious uses on the alley.