Presentation on theme: "Welcome to Address Databases Learon Dalby Arkansas Geographic Information Office Little Rock, Arkansas R. Brian Culpepper Center for Advanced Spatial Technologies."— Presentation transcript:
Welcome to Address Databases Learon Dalby Arkansas Geographic Information Office Little Rock, Arkansas R. Brian Culpepper Center for Advanced Spatial Technologies Fayetteville, Arkansas MidAmerica GIS Symposium 2002 Kansas City, Missouri
Today’s Schedule Sunday April 14, :00pm - 5:00pm 2, 15 minute breaks Outline for Lecture
General Information Location of Rest Rooms Schedule and Breaks Emergency Information
Addressing Workshop Agenda Introduction to Addressing Methods –Rural Address Procedural Overview –Urban Address Issues Geographic Base Files Overview Graphic Data Clean-up Issues Database Management Issues Student Experiences/Future Plans
Why are we interested in Address Databases ? Locate Citizen Complaints Emergency Response Permit Enforcement Incident Mapping 911
Address Database issues vary.. Dependent upon your proposed task or service. Are you in a rural county and starting from scratch? Are you in an established city with 120 yrs of addresses assigned without any STANDARDS?
Before Starting any Address or GIS project: Develop an effective plan –What questions need to be answered with these data or systems? –Know the condition of your data. –Chart how you want to get from the start to finish. Understand the capabilities of the software you will be using. –Know the limitations and strengths of the GIS/911 software –Know the limitations and strengths of the database software. Complete Pilot Project before full roll-out of any new system. Understand the capabilities of your staff, co-workers, and other partners.
Quick Review of GeoCoding Methods and Types of Locations
Some Geocoding Definitions Address Geocoding - Assigning X,Y coordinates to tabular data such as street addresses or zip codes so that they may be displayed as points on a map. Address Parity - Evenness or oddness. In address geocoding, parity is used to locate an address on the correct side of the street. –Such as, odd numbers on the left side; even on the right...
Street Address Locations (Lines) Single-Field Range Geocoding Style Dual Range (with Parity) Address Geocoding Street Centerlines are typically attributed with corresponding Address Ranges and Street Name.
Zip Code Locations (Points) Postal Codes such as 5-digit zip codes can be matched with address databases. The centroid of the Zip Code area may be used to determine the X,Y coordinate. Interpolation of +4 Zip Codes along street centerlines
Place Names or Addresses (Polygons) Tax Assessor or Parcel Databases Place Names such as City or State names may also be used to “Locate” non-graphic attribute records. Map labels are common “Locators” for other data.
The Postal Address Single most common form of geographic information May be “geocoded” to an X,Y coordinate location using a “Locator File” containing points, lines or polygons with similar address “ranges” or attributes. Street Centerlines are “interpolated” based upon Address Range (and Parity) to determine a single X, Y location.
Locating Addresses Place Names, Buildings (or Vanity Addresses) are located by linking the non- graphic table to the “spatially referenced” or graphic data. Correct Spelling and/or sensitivity settings are important when “matching attributes.” Street intersections are also common “Locators”
Geographic Base Files An overview
Geographic Base Files Definition of the GBF A Conceptual Overview DIME File History and Structure TIGER/Line Files Addressing Structure Value Added TIGER
Geographic Base Files A database of files containing cartographic and attribute information such as boundaries of geographic areas, address ranges, and street intersections. The most common GBF’s are DIME files and TIGER files. –DIME - Dual Independent Map Encoding. Developed for the 1970 and 1980 Census –TIGER - Topologically Integrated Geographic Encoding and Referencing. Developed for the 1990 Census.
Geographic Base Files May also be a referenced file containing geographic coordinates to be used for non- geographic data. Typically these files attributes include: –street names / intersections –address ranges per street segment –census tract numbers –geographic coordinates –zip code centroids, political districts, etc.
Uses of Geographic Base Files Records from an non-graphic database are linked to the matching record in the geographic database (GBF) in order to define “some” geography for that record. Geo-coding is a common term for this process. Linking a “non-spatial object ” to a “spatial object”.
GeocodingProgram Geographic Base Files Non-GraphicData Non-Graphic Data with Geocodes Conceptual Use of a GBF
Types of Geographic Base Files DIME files Dual Independent Map Encoding (DIME) files were first created in 1970 by the U.S. Census Bureau. DIME used for 1980 Census Data Collection. Flat File Structure Data update problems and only about 2% coverage of the United States.
DIME/GBF “Generic” Structure Each record contains both even and odd address geography. Contained both lat./long and State Plane Coordinates Nodes that formed Areas were ‘tagged’ with a unique ID. DB columns
Basic GBF File Structure L20L22 P14 P15 P BLOCK #10 BLOCK #6 BLOCK #7 Gadberry Dr. Big John St. Heath Ave. Malcolm Ct.. What the Geographic Base File represents. An Abstraction of Reality (street networks)
L20L22 P14 P15 P16 BLOCK #6 BLOCK #7 Gadberry Dr. GBF FILE (a Flat File) GBF FILE (Graphic Example) GBF Basic Concepts The GBF contains “Ranges” of potential addresses and “Lists” of corresponding Street Segments.
GeocodingProgram Geographic Base Files Non-GraphicData Non-Graphic Data with Geocodes Conceptual Geocoding Workflow
Another Common Geographic Base File TIGER/Line Files Acronym for Topologically Integrated Geographic Encoding and Referencing. TIGER 1989 to Present Relational Database Structure (Map data and attributes). > 50 Million geographic features that are fully integrated with the census data. Incorporated DIME and USGS Digital Line Graph (dlg) paper map products (1:100k). Complete coverage of the United States.
What is topology? Topological data structures tell the computer which cartographic objects are connected to each other logically. It defines how points, lines and polygons are related to each other on the map - an implicit relationship that is obvious to the human eye, but not explicitly defined by cartographic records within the computer.
Geographic Elements used for defining topological data structures Points - zero-dimensional objects on a map which represent a single location on the earth. Examples: –Street Intersections –Water Valves –Addresses –Fire Hydrants
Geographic Elements used for defining topological data structures Lines: one-dimensional objects on a map which represent a linear feature having a beginning point and an ending point. Lines may be subdivided into smaller units called arcs to define curves. Examples: –Street Centerlines –Lot Lines –Rivers
Geographic Elements used for defining topological data structures Polygons: Two-dimensional objects which represent shapes which have area. Polygons can be displayed and manipulated as single objects. Examples: –Census Blocks –Land Parcels –Zoning Districts
General Topologic Relationship Scheme Unique ID Feature Type X coordinate Y coordinate Unique ID Feature Type X coordinate Y coordinate Unique ID Feature Type X coordinate Y coordinate Unique ID Feature Type Beginning Point Ending Point Unique ID Feature Type Beginning Point Ending Point Unique ID Feature Type Boundary Lines PointsLinesPolygons
TIGER topology: Terms and Descriptions Node “A zero-dimensional object that is a topological junction of two or more links or chains, or an end point of a link or chain,” is a node. Entity Point “A point used for identifying the location of point features (or areal features collapsed to a point), such as towers, buoys, buildings, places, etc.” Complete Chain “A chain [a sequence of non-intersecting line segments] that explicitly references left and right polygons and start and end nodes.” The shape points combine with the nodes to form the segments that make a complete chain. Network Chains “A chain that explicitly references start and end nodes and not left and right polygons.” GT-Polygon “An area that is an atomic two-dimensional component of a two-dimensional manifold, [which is defined as] one and only one planar graph and its two-dimensional objects.”
TIGER Line Files and Addresses The TIGER/Line ® files contain address ranges, not individual addresses. The term address range refers to the first possible structure number and the last possible structure number along a complete chain side, relative to the direction in which the complete chain is coded. The address ranges are predominantly potential ranges that include the full range of possible structure numbers even though the actual structures might not exist.
TIGER Line Files and Addresses (continued) The address numbers used to create the address ranges are commonly known as city-style addresses. A city-style address minimally consists of a structure number, street name, and a 5-digit ZIP Code ® such as, 213 Main St 90210, but usually more info is provided. Address range information is stored in two record types. Record Type 1 contains the basic complete chain attributes, including one basic address range. Record Type 6 stores the additional ranges when the complete chain has more than one range on one or both sides.
Basic characteristics of address ranges The TIGER/Line ® files generally contain only those city- style address ranges used for mail delivery and do not show rural route or post office box addresses. They may contain structure numbers assigned in select areas for use by local emergency services, but not for mail delivery. Gaps may exist between multiple ranges for a single complete chain.
Basic characteristics of address ranges (continued) In a few rare cases, address ranges can include numbers with alphabetic characters. These characters help uniquely identify addresses within a county. –For instance, certain unincorporated areas of Genesee County, Michigan add a letter G prefix to the address number. The characters are consistently placed within the address range field; for example, the letter G maintains a consistent column placement in the range G1 to G99. Address ranges exist only for street features, and in some cases, corporate corridor and corporate offset boundary features.
Address Ranges Complete chains in the TIGER/Line ® files have one end point labeled as the start node and the other end point labeled as the end node (also are referred to as from and to). The start node always corresponds to the beginning of the complete chain identified by the start node coordinates FRLAT and FRLONG.
Address Ranges (cont.) The order of the addresses follows the sequence of the nodes on the complete chain; the nodes may not be related to the low to high orientation of the address range. The start address may be higher or lower than the end address for a complete chain. Structure numbers usually, but not always, systematically increase or decrease while moving along a street in a set direction from one complete chain to the next.
TIGER Address Range Example
Address Ranges and Impute Flag Codes Address Ranges Numeric characters or a mixture of numeric and alphabetic characters (maximum of 11 characters) Ranges beginning or ending with zero (0) are not valid Address range fields are blank when no address range is available. Both the start and end address range fields are blank, or both have non-zero values. The KGLADD field on Record Type 9 contains a “0” when KGL’s do not have a valid address. Impute Flags (1-character numeric code) Blank— No address range available 0— Not imputed 1— Imputed
Address Ranges and Impute Flag Codes Limitations Users of the address ranges in the TIGER/Line ® files should check for address range overlaps, gaps, odd/even reversals, and other situations that may be incorrect. While the Census Bureau continues to edit for, and correct these situations, it is possible that some still exist. Record Linkages The TLID field links Record Types 1 and 6. Since a complete chain can have more than one set of address ranges, multiple Type 6 records can exist with the same TLID. The TIGER/Line ® files distinguish these records with a record sequence number (RTSQ). The files do not contain a field indicating whether a Type 6 record exists for a specific TLID; the user must scan any existing records in Record Type 6 for a TLID match.
Multiple and Out-of-Sequence Address Ranges
Address Range Special Cases
Imputed Address Ranges Imputed address ranges occur during the process of updating the Census TIGER ® data base when a new complete chain intersects an existing complete chain with address ranges. The intersection splits the existing complete chain and produces two new complete chains connected by a new node located at the intersection point. The update program divides the old address ranges among the two new complete chains and imputes the address range ends at the new node. The impute flags identify address ranges that have been through the impute process. Each record in the TIGER/Line ® files contains four separate 1-character impute flag fields, one for each address range end.
Address Range Imputes - Before Split
Address Range Imputes - After Split
Address Range Record Locations Record Type Field Name Description 1 FRADDL Start Address, Left 1 TOADDL End Address, Left 1 FRADDR Start Address, Right 1 TOADDR End Address, Right 6FRADDL Start Address, Left 6 TOADDL End Address, Left 6 FRADDR Start Address, Right 6 TOADDR End Address, Right 9 KGLADD Key Geographic Location Address
Impute Flag Record Locations Record Type Field Name Description 1 FRIADDL Start Imputed Address Flag, Left 1 TOIADDL End Imputed Address Flag, Left 1 FRIADDR Start Imputed Address Flag, Right 1 TOIADDR End Imputed Address Flag, Right 6 FRIADDL Start Imputed Address Flag, Left 6 TOIADDL End Imputed Address Flag, Left 6 FRIADDR Start Imputed Address Flag, Right 6 TOIADDR End Imputed Address Flag, Right
Third Party Data Providers Geographic Data Technology (GDT) –Dynamap 2000 –Updated TIGER addresses and Street Centerlines –Don Cook has been doing this stuff since DIME –Census Bureau even buys their stuff! ETAK –Very good product as well! DataMetrix, Inc.
Graphic Data Clean-Up Issues Section IV
Graphic Data Clean-up Very Important if you plan to use existing CAD or GIS data from another agency, department, or private vendor as a base map. Error Correction before you begin is key. –Spatial errors (ie projection/coordinate systems) –Topological (duplicate lines, gaps, dangles, etc.)
Graphic Data Clean-up (cont.) Existing Attribute linkages on the graphics can also cause “headaches”. Particularly if you plan to use graphics that were attached to databases. Those “old” linkages can cling to the graphic elements and cause troubles later. Potential errors are dependent upon which GIS or 911 software is being implemented.
Line Weeding Line Weeding reduces the size and complexity of linear data based on a user defined tolerance Line Weeding performs distance checks on linear data Benefits of weeding linework: –Significant improvement in screen update times, plot-stroking performance, and spatial analysis processing time –Reduced disk space requirements
Cleaning CAD Linework The line cleaning tools correct errors in 2-D and 3-D linework. The line cleaning tools can: –correct undershoots or overshoots –break intersections –remove short segments –merge duplicate line segments The line cleaning tools can process: –lines, line strings, arcs, curves, shapes, ellipses, complex strings, and complex shapes
Common Line work checks Intersection Processing -- either break or flag intersections. Duplicate Line Processing -- merges duplicate line work in 2-D and 3-D design files. Short Segment Processing -- removes zero-length lines and short segments that have at least one free endpoint in 2-D and 3-D line work. Endpoint Processing -- corrects or flags free endpoints, the free endpoints can be either overshoots or undershoots.
Graphic Attributes also need to be checked TIGER Address Ranges, for example, are often incorrect (or blank) in Rural areas. Can be corrected and updated, but its tedious work! Allow me to demonstrate, using a very simple set of data and GIS software package.
Attribute Edits Selected a street segment with a “NULL” value for the address column.
Attribute Edits Edit the Attribute Table to reflect the address ranges on the left and right side of the street. Geocode a sample address.
Attribute Edits Confirm that the street segment is properly oriented for placing the “odd” address on the correct side of the street. 105 Gadberry Dr.
Attribute Edits Re-edit the Attribute table. Reverse the increase in value in the left and right address columns.
Attribute Edits Geocode the same address as before. Resulting geocode location will be the opposite end of street segment.
Attribute Edits This is overly simplified for the purpose of this demonstration, but this is basically how you could go about updating the TIGER data for a county.
Positional and Temporal Accuracy in Address Databases Our Primary Challenge !
Spatial Data Challenges Identifying Changes in our “service area” before an emergency or service call... Positional Accuracy discrepancies between data sources… Example: Comparing TIGER line data to Digital Ortho-rectified Photography
Database Management Issues of interest to Address Databases
Database Overview Agenda Database Components Example Data Types Table Indexes Domains Joins and Views Foreign and Primary Keys
Database Components Table 8 Table 6Table 7 Table 5 Table 4 Table 2Table 3 Table 1 A database is the sum of all information you have obtained. col1col3col2col4col5 Columns/ Fields Record/Row 1 Record/Row 2 Record/Row3 Record/Row4 Table 3 Database
Sample Column Data Types Character Stores a maximum of 240 ASCII characters. Integer Stores an integer in a range -2,147,483,648 to 2,147,483,647 Smallint Stores an integer value in the range -32,768 to 32,767 Double Stores a real value in double precision floating point format Real Stores a real number value as a single precision floating point Decimal Stores a fixed point decimal number with a optional precision and scale Timestamp Stores a timestamp with ‘yyyy-mm-dd:hh:mm:ss’ format
Table Indexes A table index contains information from a specified table and column The index allows you to sort information by column and place this information in a table Indexes can be placed on columns that are frequently used in queries and have few repeating values Indexes help to improve performance on queries A unique index can be created on a column that will have unique values for each record
Domains and DB Integrity A domain allows you to check the validity of an entry into a column in a database table against a corresponding set of allowable values for that column Two types of domains exist –Range domain -- used with numeric data and consists of one or more inclusive minimum-maximum ranges –List domain -- used with character data and consist of a set of character strings Domains are stored in a series of domain tables
Relational Join A Join is a linkage between two tables in the database Columns from each table with like data types are used to establish the join relationship There must be one identical value in the joined columns in each table to complete the union parcel_idparcel mslink mapid parcel_no county_name area_sqft owner parcel_id assessed_value zone_class school_district land_use
Database Views A view is a window that allows you to analyze selected columns of joined tables. A view can be defined using either a single join or multiple join relationships (ie using several DB columns). Views are used for Query, Analysis and reporting of Database Values. Makes huge DB Tables more user-friendly.
Primary Keys General Guidelines Should be numeric Must be Unique Do not change The shorter the better Automatically Generated is best... Just Call them the “Record ID’s” in a Database Table... Column Names *
Foreign Keys Should/Must have a matching column in another table with, at least some, matching values. Require extensive planning during Database Development Phase. Should be unique and numeric, but don’t have to be…. Essentially the “Linkage Columns” between Database Tables...
What’s a Cartographic Feature Something from the real world represented in your digital map: streets, streams, houses, trees, etc. A graphic element that contains a pointer to a record in the Feature table mslinkfnamefcodeftypecategoryfweightflevelfcolorfstyletabledigcmdother... 1 roadrd1line CAD Graphics Table Digital Map
Database Linkages on CAD Graphics CAD File Graphics DMRS DMRS “Old” DB Table ID record ID in “Old” Table feature link attribute link The Database software will interpret the “old linkage code” to determine what table the graphic elements “points” to.
1:2 Sides Table Segment Table Joining Tables (DBMS) 1: Many Foreign Keys in each table are used to complete the Join Relationships from Table to Table. Street Name Table
Joining Tables (example) Street Name Table Segment Table in Graphics Segment Table 1:1 Master Address File
Address Database Design Issues Determine your “Audience” and their needs. What’s your Geographic Extent? What Partnerships should be established? Establish Standards Early! Re-evaluate those Standards Regularly
Address Tables Parse the entire Address Record –Always easier for “us average” DB users to “merge” columns, rather than “split” them. Pay close attention to Primary Keys and Foreign Keys during the Design and Testing Phase. Conduct a Pilot Study for the entire database structure before going “live”.
Address Tables (continued) Use Domains to control user input at EVERY opportunity! –List Domain (valid Street Names) –Range Domains (valid numeric ranges) If gathering new addresses from more than one source, collect them in “dummy” tables before the DB “gatekeeper” cleans them up and dumps them into the “master database”.
Address Data Entry Specific data entry recommendations include: 1) Zip code entry first, with automatic fill of State and (optionally) locality data. 2) Support on-line entry with help screens, pop-up valid values access, and immediate edits. 3) Secondary unit data entry separate from street address (optionally before street for emphasis). 4) Addresses entered with manual overrides of edits should be flagged for future review. 5) Allow search for Zip code given City and State (optional).
Recommended Address Edits Several types and levels of edits may be practical, depending on circumstances and business purpose. 1) Check entered data for valid abbreviations. (Abbreviation standards used by the USPS are included in Appendix B.) 2) Compare entered location(City) and State to Zipcode (based on GCS or equivalent table information). 3) Check Zipcode for validity (based on GCS or equivalent table information). 4) Compare entered address against valid addresses: Against an existing database containing addresses (within the enterprise)
Recommended Address Edits (continued) 5) Verify and correct the standard use of state code, standard spelling for city; and presence of standard street type. 6) Inspect Street numbers that seem to represent ranges of addresses, such as street numbers in a range or the use of terms such as "scattered sites". (This only applies for those applications that receive addresses representing, for example, blocks of apartments). 7) Identify and correct building name substitutions for street addresses to the extent possible. Using COTS software modules, against a postal- service database of 140 million valid addresses. 8) If County Code is missing, generate County Code.
Recommended Address Edits (continued) 9) Identify where range of latitude or longitude is more than 5 miles. Inspect and correct. (This is a way to measure if the geocoding center is of a Zip code, rather than to a specific street address. This is unnecessary if the geocoding level is specified in a code, as is recommended). 10) Identify and delete official verbiage. For example: "Township of", "The Commonwealth of", "The Great State of". 11) Comma Check. The USPS recommends not using commas or other dividers within addresses, except the hyphen in Zip+4. The USPS further recommends all capital letters, to aid machine readability.
Recommended Address Edits (continued) 12) Enforce Business Rules. For example, it may be a rule that P.O. Box numbers (and equivalent) may not substitute for Street names (and equivalent) if the address is for a property in which the enterprise holds an interest (as opposed to the mailing address of an individual or organization).
Database Loading Tools useful for enhancing your GBF data. Bulk Update –Attributes Area Loader –Polygons Length Loader –Lines Point Loader –X, Y coords. from DB Label Loader –from graphics to the database!
Third-Party Database “Scrubbers” Clean up un-parsed Address Databases. Remove duplicate records or misspellings. Can even Geocode database records for you. Some provide CASS certified services for Address clean-up.
Web Sites of Interest
Rural Addressing Methods
There are two primary means of means of assigning locatable addresses: Distance Based Addressing: according to the number of incremental units from the beginning of a road. Grid Based Addressing: according to a pre- defined grid.
Rural Addressing Distance-based Method Distance-based addressing establishes house-numbering according to the number of increments from the beginning of a road. An increment can be any number of feet or division of miles.
Rural Addressing Distance-based Method (cont.) An increment can be any number of feet or division of miles. Typical increments are 5-feet, 5.28-feet (.001 miles), 10-feet, 25-feet, 26.4-feet (.005 miles), 50-feet, feet (.01 miles) and 100-feet.
Rural Addressing Distance-based Method (cont.) That is, by proceeding up a road, a new address is available at each multiple of this increment. In addition, the parity (odd/even) of the address is established according to the side of road. The side-of-road is relative to a vehicle proceeding along the road in the direction of ascending numbers (from the beginning of the named road odd numbers on the left and even numbers on the right. Note: there are no USPS, NENA or other known national standards for establishing parity.
Rural Addressing Grid-based Method Grid addressing establishes a northing and easting coordinate system for your municipality. Addresses are then developed from the east-west coordinate (x) plus the north-south coordinate (y). Numbers tend to be very large as each coordinate value is generally 3-digits. If the municipality covers a large area, other numbers may need to be added to indicate the sector of the grid. In addition, any road that curves back in an east-west direction can have addressing that is out of order (goes up and down). This system may be suitable in flat areas where almost no curved roads exist and the residents don't mind large numbers.
Rural Addressing Methods Official street numbers should proceed from a logical point of origin and should be in proper numerical sequence in relation to other lots with frontage on the same street/road. It is recommended that a county adopt a standard numbering sequence that goes from East to West and South to North. Odd numbers are commonly assigned to the left side of the street and even numbers to the right side of the street.
Rural Addressing Methods Address numbers should be assigned to all structures which are inhabited or which have or may have phone service (including telephone booths) and not to lots and parcels. Many lots have more than one structure and thus require more than one address. Corner lots should be assigned a number according to the frontage of the main entrance and/or where the driveway meets the road - not where the mailbox is located.
Rural Addressing Methods The logical/grammatical order of address elements should follow USPS conventions: street number, pre- directional, primary street name, suffix, post- directional, and secondary number, if any (e.g., 100 W Main ST SE Apt 201) Multi-unit structures should be given one primary number (e.g., 101 Main ST or 103 Main ST) and apartments or suites should be given numbers or letters as secondary location indicators (e.g., 111 Main ST, APT 101)
Rural Addressing Methods Primary street numbers should not be longer than six characters There should be no fractional addresses (e.g., 101 1/2 Main ST) Alphanumeric primary or secondary address numbers should not be used (e.g., EOI Main ST) Hyphenated primary or secondary address numbers should not be used (e.g Bell ST)
Rural Addressing Methods Significant leading zeros in primary and secondary numbers should not be used (e.g., 0145 Main ST) One letter road names should not be used (e.g., B Street or Z Lane) Common practice is to number from east to west, and from south to north Where one road starts and ends at points on a second road (creating a loop), the numbering along the two roads should be in the same direction
Adopting and Standardizing a System for Addressing Municipalities planning an enhanced project should establish a single locatable addressing system that is adopted for all addressing purposes including emergency service provision, postal delivery, municipal record keeping, and utility service orders.
Address Increments NENA Standards recommend that communities adopt a 5.28' increment. This increment would allow for 1,000 unique numbered addresses per 1 mile length of road (there are 5,280 feet in a mile). This increment makes it very easy for an emergency service provider in the event of an emergency to look at the address and quickly figure out how far down the road the house is located. For example, if an ambulance were dispatched to 500 Alpine Lane (using a 5.28' address increment) the emergency vehicle would know to travel exactly one half mile down Alpine Lane to locate number 500.
Address Increments (cont.) Another benefit of the 5.28' increment is that structures can be assigned an address every 10.5' on each side of the driveway. This means that many addressees are developed, mainly for navigational purposes, but also for future development needs of a community. If the appropriate measured numbering system is selected, a community will never need to be re-addressed to accommodate future development.
Local standards are a customization of the nationally recommended methods Addressing Standards that should be considered on the local level Establish a Committee to implement County-wide Standards. Establish Road Naming and Re-naming Standards. Establish a Road Measuring and Numbering System that Fits your county. Establish Addressing Standards that would require residents to receive a new E-911 Address.. Establish Road Signs and Address Number Standards. Consider Hiring a GIS/E911 Consultant.
Road Sign & Address Numbering Naming roads and mapping them is among the first steps in an addressing process. Placing road signs is one of the final tasks. To assist both emergency service personnel and the general public, signs must be visible and maintained. A frequent compliant about road signs is that they are often hidden by tree branches. Annual trimming can eliminate this problem.
Road Signs There are several varieties of signs that are suitable for public road use. The most common is the green background with reflective white lettering. However, regardless of color, the important issue is to ensure the letters are tall enough to be easily seen day or night. Sizes: Lettering on street name signs should be at least 4 inches high, supplementary letting to indicate the type of street (e.g., Street, Avenue, Road, etc.) or section of city (e.g., N.W.) may be in smaller lettering, at least 2 inches high. For rural areas: Municipalities should use 9 inch high blade in lengths of 24, 30, 36, or 42 inches with 6 inch high letter for street names, 4 inches for other.
Road Signs (cont.) For urban areas: Municipalities should use 9 inch high blade in lengths of 24, 30, 36, or 42 inches with 4 inch high letter for street names, inches for other. Placement: In business districts and on principal arteries, Street Name signs should be placed at least on diagonally opposite corners so that they will be on the far right hand side of the intersection for traffic on the major street. They should be mounted with their faces parallel to the streets they name. In residential districts at least one Street Name sign should be mounted at each intersection. In rural districts signs should be placed to identify important roads not otherwise marked.
Basic Rural Addressing Tasks Determine the type of address numbering system(s) to be used. Establish base maps for the entire area by using existing data or developing you own centerline file. Determine ESN boundaries, telephone exchange boundaries, city limits, and zip code boundaries. Research new developments, streets and sub-divisions for centerline updates.
Basic Rural Addressing Tasks (cont.) Determine property number ranges. Establish address standards and draft addressing ordinances Build Master Street Address Guide (MSAG) and supply to USPS, telephone companies and others. Determine a time-line for establishment and adaptation of new address for rural structures.
Basic Rural Addressing Tasks (cont.) Obtain citizens address and location records from all possible sources. Locate every addressable structure from field verification or aerial photography. Assign a property number to each structure or driveway location on map.
Basic Rural Addressing Tasks (cont.) Use citizen/location records and/or fieldwork to verify name, telephone number and existing (old) address for each structure. Match new property addresses with old address data to create an Address Change File. Inform the USPS, telephone company, citizens and others of the change of address and the date in which the change will become official for mailing purposes.
Basic Rural Addressing Tasks (cont.) Work with telephone companies and the USPS on follow-up and error correction. Develop methods for address assignment by cities and counties. Deliver indexed maps and atlases to cities and county. Establish a rigorous Data Maintenance schedule and keep up with it by hiring qualified personnel.
Methods for locating Address Changes Address Listings/Files - maintained by your government (including those used for mass mailings or needed to provide essential services, such as police, fire or sanitation programs) or purchased from commercial vendors are an acceptable source for creating housing unit tallies for each census block, provided they are current and comprehensive. You also can update comprehensive address listings/files with additions and deletions from other local records. Tax Assessment Records - may supply up-to-date tallies of housing units. Utility Connection Records - (electric, gas, water or sewer) are other sources for developing housing unit tallies.
Other Methods for “Change Detection” Multiple sources: Property Permit Records Certificates of Occupancy and Demolition Permits Neighborhood visits Special censuses Aerial photography (DOQQ’s) and Current land use maps Housing authorities records Tribal, village, or Indian Health Service Environmental Health Office records
When should Addresses be Updated or Checked? Local governments are in the best position to identify areas with potentially missing or incorrectly assigned addresses. For example: Has there been recent new construction activity in your community? Are there areas that have changed from single-family homes to multi-family homes and vice versa? What about commercial or former public buildings that have been converted to residential use? Are there new mobile home parks or even scattered new mobile homes? Do you have apartment buildings or boarding houses with irregular or missing numbering schemes for the individual units? Are there blocks where you believe the Census Bureau missed housing units in 1990? Has your community recently annexed new territory, and thus new addresses?
Urban Addressing Issues
Most Common Address Systems in Urban Areas: –Base Line Method: References for an Addressing Grid use paired perpendicular lines oriented North/South and East/West. –Quadrants: Four Zones of a city, quartered “roughly” by a pair of perpendicular lines. –Addressing Grid: Ranges for addresses are forced onto the existing perpendicular street network
Urban Addressing Issues (cont.) Mostly dealing with new Street Naming and Standardization. Continue to edit and update Address Standards. Vacant Parcels will require an Address, unlike the suggested Rural methods.
Common Urban Address Range Methods Interval - Much like the distance method used in the rural areas, where every so many feet there’s a new number. Potential Range - Address numbers eligible for assessment along a block (typically 100) Actual Range - Address numbers actually assigned along a block ( ) not ( ).
Urban Address Issues (cont.) Adjacent Municipal Jurisdictional conflicts. –County verses the City? Who wins? Annexations and the expansion of existing addressing grids. Development of an effective code for Street Naming/Addressing conventions and methods. –Especially for contemporary sub-divisions
Urban Addressing Issues (cont.) Expansion of addressing into Rural Areas with an existing 911 addressing scheme. Dealing with “prestige” or “vanity” addresses. Issuing change of address notices. Keeping current updates among various agencies. Cooperation is the key to success….
Addressing Standards and Related Issues
Addressing Database Standards Kansas Missouri Michigan Arkansas Examples are provided on the CD-ROM