Traffic Analysis Zones' (TAZ) Employment Data

Metadata also available as

Metadata:

Identification_Information
Data_Quality_Information
Spatial_Data_Organization_Information
Entity_and_Attribute_Information
Distribution_Information
Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator: Loudoun County, VA, Department of Planning, Demographer
Publication_Date: 20140326
Title: Traffic Analysis Zones' (TAZ) Employment Data
Geospatial_Data_Presentation_Form: tabular digital data
Other_Citation_Details:: Loudoun County's Traffic Analysis Zones (TAZ) were delineated by Loudoun County Government in cooperation with the Metropolitan Washington Council of Governments (MWCOG). The TAZ layer has been modified from the MWCOG TAZ GIS layer. When the MWCOG GIS layer is overlaid with Loudoun County Government's detailed GIS layers it can be determined that the MWCOG TAZ boundaries in some cases are slightly off from the actual location of the physical features, natural features, and governmental units such as town boundaries that they are designated to follow. The Loudoun TAZ layer was generated by Loudoun County so that the TAZ boundaries would overlay with the features in Loudoun County's GIS data sets that the boundaries are designated to follow. The forecasts for the TAZs are updated by Loudoun County generally once every year to account for changes in market conditions, rezonings, and comprehensive plan amendments. The TAZ boundaries remain unchanged for a period of about ten to fifteen years.

Description:

Abstract:: The employment data represents Loudoun County's Round 8.3 Metropolitan Washington Council of Government's Cooperative Forecasts as of March 7, 2014. Employment data from 2011 provides a basis for the forecasts. The data includes the total numbers of jobs estimated to be in Loudoun County in 2010 and expected to be in Loudoun from 2015 through 2040 in five-year increments by Traffic Analysis Zones (TAZ). The employment forecasts are divided into five categories: 1) total employment, 2) industrial employment, 3) office employment, 4) retail employment, and 5) other employment. Forecasts for the TAZs are produced by Loudoun County by accounting for regional and local market trends, zoning, planned land use, and the long-range supply of land.
Purpose:: The current TAZ boundaries are used for statistical data tabulation purposes, including the current MWCOG cooperative forecasting rounds and future forecasting rounds through approximately 2020. TAZ forecasts are used for demographic analyses of Loudoun County, as well as for Loudoun County and Washington, D.C. regional planning purposes. A detailed picture of population, housing, and employment, within a TAZ is gained from the TAZ forecasts. TAZ forecasts are also used extensively for transportation modeling and transportation planning.
Supplemental_Information:: Data are stored in the corporate ArcSDE Geodatabase as a polygon feature class. The coordinate system is Virginia State Plane (North), Zone 4501, datum NAD83 HARN (vertical datum, if applicable, NAVD88), US Survey foot units.

Status:

Progress: Complete
Maintenance_and_Update_Frequency: Irregular

Keywords:

Theme:

Theme_Keyword_Thesaurus: None: Employee generated
Theme_Keyword: population
Theme_Keyword: boundary
Theme_Keyword: boundaries
Theme_Keyword: demographic
Theme_Keyword: TAZ
Theme_Keyword: traffic
Theme_Keyword: COG
Theme_Keyword: housing units
Theme_Keyword: household
Theme_Keyword: region
Theme_Keyword: forecast

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Categories
Theme_Keyword: society
Theme_Keyword: boundaries

Place:

Place_Keyword_Thesaurus: None: Employee generated
Place_Keyword: Washington
Place_Keyword: Virginia
Place_Keyword: D.C.
Place_Keyword: 51107
Place_Keyword: DC
Place_Keyword: County
Place_Keyword: Loudoun

Access_Constraints: None

Use_Constraints:

These data were generated for use by Loudoun County and are available to the public. These data are intended for use at 1:2400 scale or smaller. Acknowledgement of Loudoun County would be appreciated in products derived from this data.

Point_of_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Loudoun County, VA, Department of Planning

Contact_Position: Demographer

Contact_Address:

Address_Type: mailing and physical
Address: 1 Harrison St, SE
Address: MS 62
City: Leesburg
State_or_Province: VA
Postal_Code: 20175
Country: US

Contact_Voice_Telephone: (703) 777-0246

Contact_Facsimile_Telephone: (703) 777-0441

Contact_Electronic_Mail_Address: dop@loudoun.gov

Hours_of_Service: 8:30-5:00 EST, M-F

Native_Data_Set_Environment:

Microsoft Windows Server 2008 Version 6.0 (Build 6002) Service Pack 2; ESRI ArcGIS 10.0.5.4400

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report:: Retention of attribute accuracy throughout the personal geodatabase or shapefile to ArcSDE geodatabase feature class coversion process was ensured by a manual or automatic QA/QC programmatic check. To meet satisfactory QA/QC requirements the input coverage and output feature class must have, on a record by record basis, identical attribution when comparing all concatenated fields to all the user-defined attribution.

Logical_Consistency_Report: Topologically clean

Completeness_Report:

Features may have been eliminated or generalized due to scale and intended use. To assist Loudoun County, Virginia in the maintenance of the data, please provide any information concerning discovered errors, omissions, or other discrepancies found in the data.

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:: Retention of coordinate accuracy throughout the personal geodatabase or shapefile to ArcSDE geodatabase feature class conversion process was ensured by a manual or automatic QA/QC programmatic check. To meet satisfactory QA/QC requirements the input coverage and output feature class must have the same record total, and on a record by record basis, area, perimeter, and length differential of less than +/- 0.5%.

Lineage:

Source_Information:

Type_of_Source_Media: None

Source_Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 20100101

Source_Currentness_Reference: Unknown

Source_Contribution:

TIGER/Line files provided the foundation upon which census blocks were drawn. The 2010 Census blocks were the basis for devising the TAZ boundaries.

Source_Information:

Type_of_Source_Media: None

Source_Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 20110101

Source_Currentness_Reference: Unknown

Source_Contribution:

Loudoun County Government GIS digitized block lines for aligning TAZ data with Loudoun County GIS data

Source_Information:

Source_Citation:

Citation_Information:

Originator: Loudoun County Department of Management and Financial Services
Title: Loudoun County Department of Planning
Geospatial_Data_Presentation_Form: spreadsheet

Type_of_Source_Media: hardcopy

Source_Citation_Abbreviation: Loudoun County Department of Planning

Source_Contribution:

Loudoun County Department of Planning is the source for population, housing units, households, and employment for TAZs.

Source_Information:

Type_of_Source_Media: onLine
Source_Contribution:: The 2010 Census SF1 block data were the basis for deriving the demographic data.

Process_Step:

Process_Description:

The following is a description of the process used to derive the 2010 to 2040 employment. First, the forecasting of new building square footage for each type of employment is performed for TAZs using issued building permits, zoning, planned land use, local market trends, the long-range supply of land, and guidance from the Loudoun County Department of Economic Development and Loudoun County Fiscal Impact Committee, a Loudoun County Board appointed committee. The forecasted new employment by employment type is then calculated by multiplying the forecasted square footage of an employment type by a ratio of estimated persons per thousand square feet for an employment type. In some cases the results are then adjusted using sound and reasonable judgment due to the ratio of persons per thousand square footage for an employment type being too high or too low for certain types of businesses (e.g. data centers). A TAZs total employment for 2010 to 2040 is forecasted by using a 2008 employment database of total employees by establishment and adding the TAZ's total new employment forecasted to the base total employment number.

Process_Contact:

Contact_Information:

Contact_Organization_Primary:

Contact_Organization: Loudoun County Department of Planning

Contact_Position: Demographer

Spatial_Data_Organization_Information:

Indirect_Spatial_Reference: Loudoun County

Point_and_Vector_Object_Information:

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: Entity point
Point_and_Vector_Object_Count: 0

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: Entity point
Point_and_Vector_Object_Count: 812

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: Entity point
Point_and_Vector_Object_Count: 161

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: GT-polygon composed of chains
Point_and_Vector_Object_Count: 282

SDTS_Terms_Description:

SDTS_Point_and_Vector_Object_Type: GT-polygon composed of chains
Point_and_Vector_Object_Count: 161

Entity_and_Attribute_Information:

Detailed_Description:

Entity_Type:

Entity_Type_Label: GISDBB.GISBROW.TAZ_EMPLOYMENT

Attribute:

Attribute_Label: Ret_2010

Attribute_Definition: Estimated number of Retail jobs in 2010

Attribute_Definition_Source: Department of Planning