Utah SGID vector-format GIS data is now accessible for downloading through two new index pages on the GIS portal website. The new index pages allow users to access vector data layers through a listing by name or by data category. The new indexes can be accessed from the left navigation menu's GIS Resources button (see below).
The old application to generate a list of layers given a user selection from a list of categorys, extents, and file formats is still available but its menu button has been renamed to 'Data Selector'
SGID.U024.ZipCodePOBoxes is a feature class than can be used to approximate the location of PO Box addresses. Many 5 digit zip codes exist soley to support PO Box delivery and contain not street deliver addresses at all.
Several minor changes were made to this dataset today (7/14/08) to correct the position of the Brianhead and Monroe post offices and to add a point for the Herriman post office.
The following update has been made to GIS data residing on the State Geographic Information Database’s ArcSDE server, gdb92.agrc.utah.gov (v9.2):
The SGID U024.Transportation.StatewideStreets feature class has been updated on the SGID ArcSDE Database Server. Shapefiles and File-Based Geodatabase files for StatewideStreets are also available for download on the SGID FTP site. Geocoding services, ArcIMS Applications, and ArcGIS Server Applications & Web Services are now using this new data.
Important note: This new data implements the new 84081 and 84721 zip codes made in West Jordan and Cedar City [more information] so if you're using this data for geocoding, you'll want to make sure that your address data carries the new zip codes in these areas.
The update includes (by geographic extent:
Statewide: CFCC vs. ALT_NAME vs. S_TYPE attribute improvements; LABEL field is no longer populated with SUF_DIR for alpha streets
Box Elder: Major Highway attribute improvements
Davis: ‘Schick Lane’ issue resolved - now called ‘Bonneville Lane’; geocoding/attribute improvements; Layton -updated entire dataset; edge-matching improvements (Blue Stakes of Utah edt suggections)
Duchesne: geocoding improvements between Fruitland and Starvation Reservoir
Juab: edge-matching improvements
Iron: attributed streets within the new Cedar City zip code 84721
Millard: edge-matching improvements
Morgan: geocoding/attribute improvements (Blue Stakes of Utah edt suggections)
Salt Lake County: Major Highway attribute improvements; added additional roads from features from the ‘SaltLakeCoSurveyorStreets’ layer that were not previously in dataset; zip code improvements; attributed streets within the new West Jordan zip code 84081
Sanpete: duplicated roads removed
Summit: geocoding/attribute improvements (Blue Stakes of Utah edt suggections)
Tooele: added additional roads that were not previously in dataset. And also: geocoding improvements in Stansbury Park; I-80 on/off ramp improvements (Blue Stakes of Utah edt suggections)
In response to the US Postal Service's zip code changes in West Jordan and Cedar City, effective July 1, 2008 [see detailed description], AGRC has updated the SGID's 5 digit zip code polygon feature class SGID.U024.ZipCodes to reflect the new changes. The updated dataset is now available on the SGID ArcSDE Database Server and on the SGID FTP site. AGRC is committed to updating zipcode data as the US Postal Service makes its infrequent changes -- usually in repsonse to increased development or population increases.
Please keep in mind that, while most of us think of zip codes as polygon geographic features, zip codes are really just simple mechanisms for sorting mail so that it arrives at the correct post office for distribution and in reality, the US Postal Service assigns zip codes at the block face level and only for streets that receive mail delivery. In other words, zip codes are address range based, not areal in nature.
For the SGID.U024.ZipCodes polygon GIS layer, AGRC has constructed a statewide zip code layer that approximates the boundaries at which the the real world linear-based zipcodes change. In reality the left side (ZIP_LEFT) and right side (ZIP_RGHT) zip code attributes carried by the U024.StatewideStreets are a much better representation of zip codes as geographic features. look for the U024.StatewideStreets dataset and geocoding address locators based on this dataset to be updated in the next couple days with an accompanying post to the GIS Portal.
Note: while the polygon zip code feature class definitely has its applications, representing zip codes as polygons has several disadvantages. Two of these disadvantages are:
Wherever mail is not delivered to addresses (e.g. rural routes & and areas where only post office box delivery is offered), the zip code polygons are just guesses as to how the zip code system would be extended if mail was delivered to these rural areas
Where a zip code polygon boundary follows a street centerline, it is impossible to know what zip code is to be found on a specific side of the street. The zip code on the left and right side of the boundary along the centerline could be the same or different. This information is, however, found on the left side (ZIP_LEFT) and right side (ZIP_RGHT) zip code attributes carried by the U024.StatewideStreets.
