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Fall 2007 - Tech Talk: The ABC's and 123's of Dakota County's Address Grid
by Todd Lusk
Did you know that Dakota County uses a “grid” system for naming its streets and assigning addresses? Do you know how the system works, what it based on or what its purpose is? Believe it or not, it is possible to navigate your way through most of Dakota County without the aid of a GPS, a street atlas or an online mapping website (like Google Maps, Yahoo! Maps, etc.)
Dakota County has an ordinance called the Uniform Street Naming and Addressing System (USNAS). The goal of the ordinance is to lay the groundwork for a consistent way of naming streets in the County and for assigning addresses along those streets. When applied consistently, the ordinance can be a huge benefit to people like delivery drivers and emergency responders who regularly have to navigate the County’s streets. The USNAS basically defines a “grid” that lays out street naming and address range guidelines.
Not all cities use the County’s street naming and addressing grid. Older portions of the County, which were already established prior to the enactment of the ordinance, continue to use their own naming and addressing systems.
Dakota County’s address grid is based on one-mile square cells that generally follow public land survey sections. East-west streets are given numerical names (i.e., “150th Street West”) and north-south streets are named after persons, places or things. A division line running north-south through the County marks the alphabetical starting point for names of north-south streets. That line also marks the starting point for building numbers on east-west streets with a range of 1,000 addresses (500 even and 500 odd) in each grid cell.
North-south streets on the east side of the division line bear the names of persons. Those north-south streets on the west side of the line bear the name of places or things. All names for north-south streets are in alphabetical order and begin with a new letter of the alphabet for each mile further from the division line one travels.
East-west streets have numerical names that indicate their distance south of a base line geographically in line with the State Capitol building in St. Paul (e.g., 150th Street is 15.0 miles south of the base line).
The benefit of this grid system is that we can “calculate” a theoretical address location with any given northing and easting. Because we know the name of the street, and what type of name it is (i.e., a place, thing or person), we can get a rough idea of where the street is located in the county. Then with the house number we can get a rough idea of how far south in the county we need to go.
The whole scenario gets slightly more complicated when curvilinear streets in developments come into play. It is possible for a street to “turn back” on itself and this can create problems with the house number ranges. First, because the street does not run perfectly east-west, it must be a “north-south” street per the County’s ordinance. This forces those assigning the addresses to pick a “north end” of the street. Once that is done, an east and west side of the street is determined. That, in turn, determines which side of the street will have the even and odd house numbers. It is relatively easy to keep the addresses in line with the County’s Uniform Street Naming and Addressing System ordinance when following this process.
In the end this ultimately helps emergency responders, and others, navigate their way through the County quickly and effectively. On the surface the system might seem a bit confusing, but on closer examination it’s fairly easy to understand the rationale and system behind it.
Copyright 2006 Dakota County, Minnesota
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