The Functional Basis of the Zip Code and Sectional Center System

Gregory Smith University of Washington The Functional Basis of the Zip Code and Sectional Center System IN the process of creating the present zonal system, the United States Post Office Department did not revise a set of older boundaries or simply devise a system of regionalization for administrative convenience. Other causes, primarily technological, existed and one can see the beginning effects as well. The program seems to be having consequences that are similar to both the divisive effect of political boundaries and the reinforcing effect of administrative centralizing tendencies. In order to assay those effects and to understand the functional basis of the present postal system, it is necessary to ask at least three questions: ( 1 ) What is the organizing principle of the sections? (2) How have transportation changes altered the postal system? (3) In the organization and continuing changes is there any evidence of an operational advantage accruing to commercial firms, i.e., does the zip code system offer anything useful to the large volume mailing firms? Sorting and Routing Problem A major problem facing postal authorities five years ago was that of reversing the customary scheme of sorting mail along a network of routes. Through shipments had been common. A bundle of mail tied in New York was kept intact and forwarded along the way, eventually to be sorted in California by delivery route. However, detailed knowledge of the multitude of post offices in California remained the specialized competence of the West Coast sorter. Sorting was done by men who were practiced in the intricacies of mail delivery schemes, primarily because they performed a function for which no alternative existed—the progressively detailed sorting of mail as it neared its destination. 97 98ASSOCIATION of pacific coast geographers The sorting alternatives within the context of a postal system based on state, town, and city place names admits of littie innovation. Mobile post offices were one innovation, and bottlenecks in sorting that otherwise might have occurred earlier in major cities were averted by gateway terminals (See page 103). The stubborn reality was that mail could not be presorted1 by the large bulk mailers of second- and third-class mail on any other than a highly aggregated basis, that is, by state and city. That the place-name sorting could not be improved by tinkering or by wholesale mechanization and that quick changes were unlikely can be seen by two indications of the scale of postal operations: ( 1 ) A mailer such as Luce Publications enters roughly 750 million letters and magazines into the mail flow in a single year. (2) The current roster of first- through fourth-class post offices numbers about 33,000. It is not difficult to accept the assertion that the United States Post Office is the largest business in the world.2 Zones and Clusters of Zones If improvements in sorting procedures had meager prospects as long as place designations were used exclusively, what occurred to bring about the zonal innovation? Historical studies of innovation stress a challenge-response interpretation, and one may submit for inclusion in that category the digital zone system begun during 'Presorting is die commonly used term for a mandatory ordering of masses of letters or parcels by any firm tiiat conducts its mailings under the terms of special postal permits. When many thousands of identical letters are dealt widi, die post office processes them by actual weight and estimated number after die firm places die mail in sacks or tied bundles. Thus, in return for an advantage to the firm of lower unit letter rates the postal service gains appreciably in handling efficiency. "The general scale of postal operations and specific information on die zonal system appear in Zip Code System in the United States Postal Service, hearings before die Subcommittee on Postal Facilities and Modernization, Committee on Post Office and Civil Service, House of Representatives, 89th Congress, Washington, D. C, parts I and II. An explanation of die numerical coding of regions, sectional centers, and zones has been widely circulated in Zip Code: The Last Word in Mail Addressing, Post Office Department, Washington, D. C, 1966. The historical transportation changes tiiat led to the devising of die sectional centers and the...