III.1 Introduction

This chapter discusses Geosupport’s street name processing in detail. (In this chapter, unless otherwise noted, the term ‘street name’ is used generically to encompass not only names of city streets, but also a wide variety of other New York City geographic feature names that Geosupport recognizes, including the names of some tunnels, bridges, rail lines, shorelines and geographic place names of various kinds.) The street name normalizing algorithm is briefly outlined. Two aspects of street name normalizing that are under user control, the selection of a street name normalization format and the Street Name Normalization Length Limit (SNL) parameter, are described. Other street name processing features that are described are partial street names, similar names, street name browsing, and selection of output street names for Character-Only Work Area calls . Certain non-street feature names, place names and ‘pseudo-street names’ that are recognized by Geosupport are also discussed in this chapter. The related topic of street codes is discussed in detail in Chapter IV.

It is important to note that New York City geographic names are meaningful only when the borough is identified, since features in different boroughs can have the same name. For example, all five boroughs have a street named BROADWAY. In general, the borough is identified via a borough code. For Functions 1, 1A, 1B, 1E and AP, the borough may also be identified via a ZIP code.

Applications pass up to three input streets to Geosupport in a single call, depending on the function being called. For most of the functions that accept street input, input streets are passed either in the form of street names or in the form of street codes. The exceptions are that Function 1N accepts street name input only, and the display functions, Functions D, DG and DN, accept street code input only.

Input streets are passed to Geosupport using as many as necessary of WA1’s three input street name fields or its three input street code fields. Each WA1 input street name field is 32 bytes long. If there is more than one input street in a call, they must all be of the same type, either all names or all codes, not a combination of both types. If both street names and street codes are specified in WA1, for all functions other than D, DG, and DN, Geosupport processes the street names and ignores the street codes. For functions D, DG, and DN, the street names are ignored.

When street input is in the form of street names, before attempting to identify which New York City street an input name refers to, Geosupport attempts to ‘normalize’ the name by executing a systematic algorithm intended to produce a version of the name in a standardized format. If normalization is successful, Geosupport returns the normalized street name(s) to the user in as many as necessary of WA1’s three output normalized street name fields. Geosupport’s normalizing algorithm is designed so that users have considerable leeway in spelling input street names. For example, input names may contain commonly used abbreviations for words like avenue, street, boulevard, east, etc.

When Geosupport is able to normalize an input street name successfully, it uses the normalized name to read an internal Geosupport file in order to obtain the street code. Successful normalization followed by successful street code retrieval constitutes Geosupport System validation of the input street name, i.e. its identification or ‘recognition’ as the name of a specific New York City street. Note that successful normalization alone does not constitute validation of the input street name.

Geosupport’s street name normalizing algorithm is highly customized for New York City. The algorithm is complex and a complete description of it is beyond the scope of this document. In any event, the algorithm is performed automatically, and users need to be aware primarily of two aspects that they can control. These are a parameter for controlling the maximum length of normalized street names, called the SNL; and a choice of two formats for normalizing street names, called the compact and sort formats. These features are described in detail in this chapter. For completeness of the discussion, and because some familiarity with the normalizing algorithm may aid the user in understanding possible causes of rejection, a summary description of the normalizing algorithm is also given in this chapter.

Function 1N. Function 1N can be used to normalize a street name and retrieve its street code, without having to specify a particular geographic location. Function 1N requires the input only of a borough code and a street name. The SNL parameter and the selection of a street name normalization format can be specified in a Function 1N call. Function 1N is called using Work Area 1 only.