Southern
California Roads Metadata
GEODATASET NAME: SCA_ROADSA83
IDENTIFICATION INFORMATION
Description:
Wessex roads (interstate highways, major roads, and streets) as
derived from Bureau of the Census TIGER/Line files at 1:24000
scale or smaller, for the Southern California Pilot Study Area.
Abstract:
Highways, roads, and streets derived from the Wessex TIGER/Line
shapefiles for the Southern California Pilot Study Area.
Data Type:
Coverage, line
Data Originator:
Wessex (A Division of GDT)
11 Lafayette St.
Lebanon, NH 03766-1455
1(800)331-7881
and
U.S. Department of Commerce
Bureau of the Census
Geography Division
Washington, DC
tiger@census.gov
Data Processor:
Ed Evanson
Lockheed Martin Environmental Services
1050 E. Flamingo Road, Suite E120
Las Vegas, NV 89119
(702)897-3208
eevanson@lmepo.com
Data Provider:
Dan Heggem
U.S. Environmental Protection Agency NERL
P.O. Box 93478
Las Vegas, NV 89193-3478
(702)798-2278
heggem.daniel@epa.gov
Keywords:
Wessex, roads, highways, streets, transportation, Southern California,
Pilot Study Area
Version:
N/A
Status:
Interim
Revision Number:
0
Series Name:
Online Link (URL):
Time Period of Content:
1995 TIGER/Line files
Use Constraints:
None. Acknowledgment of the U.S. Bureau of the Census would be
appreciated for products derived from these files. TIGER, TIGER/Line,
and Census TIGER are trademarks of the Bureau of the Census. Wessex
is a division of GDT, Inc.
Purpose:
Southern California data browser
Date of metadata entry/update:
1/22/2002
No Publication Information Available
No File Security Information Available
DATA QUALITY INFORMATION
Cloud Cover:
Not applicable
Software:
Arc/Info 7.2
Operating System:
Unix
Path Name:
/gis/wemap/sca/roads
Logical Consistency Report:
Not presently available
Completeness Report:
Not presently available
Horizontal Positional Accuracy:
Not presently available
Vertical Positional Accuracy:
Not presently available
Attribute Accuracy:
Not presently available
Procedures:
Using the Wessex CD extraction application, a roads shapefile
containing interstate highways, major roads, and streets was
extracted from the CDs for each relevant county. The shapefiles
were merged together and clipped to the Southern California boundary
using Arcview's geoprocessing wizard. The resulting Arcview Shapefile
was converted to an Arc/Info coverage and projected to region 9
Albers projection.
Reviews Applied to Data
Lockheed Martin Environmental Services internal review
Related Spatial Data Files:
All geodatasets with sca_ prefix.
Other References Cited:
Notes:
Update Frequency:
As needed
SPATIAL REFERENCE INFORMATION
Description of DOUBLE precision coverage sca_roadsa83
FEATURE CLASSES
Number of Attribute Spatial
Feature Class Subclass Features data (bytes) Index? Topology?
------------- -------- --------- ------------ ------- ---------
ARCS 658177 266 Yes
NODES 515151
SECONDARY FEATURES
Tics 4
Arc Segments 1272636
TOLERANCES
Fuzzy = 40.300 N Dangle = 0.000 N
COVERAGE BOUNDARY
Xmin = -357114.180 Xmax = 45882.137
Ymin = 3399735.963 Ymax = 3658714.160
STATUS
The coverage has not been Edited since the last BUILD or CLEAN.
COORDINATE SYSTEM DESCRIPTION
Projection ALBERS
Datum NAD83
Units METERS Spheroid GRS1980
Parameters:
1st standard parallel 33 15 0.000
2nd standard parallel 40 15 0.000
central meridian -116 45 0.00
latitude of projection's origin 0 0 0.000
false easting (meters) 0.00000
false northing (meters) 0.00000
ENTITY AND ATTRIBUTE INFORMATION
Annotation Name:
ATTRIBUTE LISTING FOR: sca_roadsa83.aat
COLUMN ITEM NAME WIDTH OUTPUT TYPE N.DEC ALTERNATE NAME INDEXED?
1 FNODE# 4 5 B - -
5 TNODE# 4 5 B - -
9 LPOLY# 4 5 B - -
13 RPOLY# 4 5 B - -
17 LENGTH 8 18 F 5 -
25 SCA_ROADSA83# 4 5 B - -
29 SCA_ROADSA83-ID 4 5 B - -
33 SUB# 4 5 B - -
37 SUB-ID 4 5 B - -
41 W06111R_ID 8 11 F 0 -
49 CFCC 3 3 C - -
52 COLOR 12 12 C - -
64 FDPRE 2 2 C - -
66 FNAME 30 30 C - -
96 FTYPE 4 4 C - -
100 FDSUF 2 2 C - -
102 LEFTADD1 8 8 C - -
110 LEFTADD2 8 8 C - -
118 RGTADD1 8 8 C - -
126 RGTADD2 8 8 C - -
134 ZIPL 5 5 C - -
139 ZIPR 5 5 C - -
144 LEFTZONE 44 44 C - -
188 RIGHTZONE 44 44 C - -
232 TRACT_AVL 12 12 C - -
244 TRACT_AVR 12 12 C - -
256 TLID 10 10 C - -
METADATA REFERENCE SECTION
FGDC Content Standards for Digital Geospatial Metadata
FGDC Standards Version 6/98 / metadata.aml ver. 1.3 5/21/99
SUPPLEMENTAL METADATA (where available)
Description:
Abstract: TIGER, TIGER/Line, and Census TIGER are trademarks of the Bureau
of the Census. The 1995 TIGER/Line files are an extract of selected geographic
and cartographic information from the Census TIGER data base. The geographic
coverage for a single TIGER/Line file is a county or statistical equivalent
entity, with the coverage area based on January 1, 1995 legal boundaries. A
complete set of 1995 TIGER/Line files includes all counties and statistically
equivalent entities in the United States, the U.S. Virgin Islands, Puerto Rico,
American Samoa, Guam, the Southern Marian Islands, U.S. Minor Outlying Areas,
and the Pacific Island Territories. The Census TIGER data base represents a
seamless national file with no overlaps or gaps between parts. However, each
county-based TIGER/Line file is designed to stand alone as an independent data
set or the files can be combined to cover the whole Nation and its territories.
The 1995 TIGER/Line files consist of line segments representing physical
features and governmental and statistical boundaries. The files contain
information distributed over a series of record types for the spatial objects
of a county. There are 17 record types, including the basic data record, the
shape coordinate points, and geographic codes that can be used with appropriate
software to prepare maps. Other geographic information contained in the files
includes attributes such as feature identifiers/census feature class codes
(CFCC) used to differentiate feature types, address ranges and ZIP Codes, codes
for legal and statistical entities, latitude/longitude coordinates of linear
and point features, landmark point features, area landmarks, key geographic
features, and area boundaries. The 1995 TIGER/Line data dictionary contains a
complete list of all the fields in the 17 record types.
Purpose: In order for others to use the information in the Census TIGER data
base in a geographic information system (GIS) or for other geographic
applications, the Census Bureau releases to the public extracts of the data
base in the form of TIGER/Line files. Various versions of the TIGER/Line files
have been released; previous versions include the 1990 Census TIGER/Line files
(version 0003), the 1992 TIGER/Line files (version 0005), and the 1994
TIGER/Line files (version 0021). The 1995 (version 0024) TIGER/Line files were
originally produced to support Phase I of the Census 2000 Redistricting Data
Program.
Maintenance_and_Update_Frequency: TIGER/Line files are extracted from the
Census TIGER data base when needed for geographic programs required to support
the census and survey programs of the Census Bureau. No changes or updates
will be made to the 1995 TIGER/Line files. Future releases of TIGER/Line files
will reflect updates made to the Census TIGER data base and will be released
under a revised version numbering system (based on the month and year the data
is extracted).
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report: Accurate against Federal Information Processing
Standards (FIPS), FIPS Publication 6-4, and FIPS-55 at the 100% level for
the codes and base names. The remaining attribute information has been examined
but has not been fully tested for accuracy.
Logical_Consistency_Report: The feature network of lines (as represented by
Record Types 1 and 2) is complete for census purposes. Spatial objects in
TIGER/Line belong to the "Geometry and Topology"(GT) class of objects in the
"Spatial Data Transfer Standard" (SDTS) FIPS Publication 173 and are
topologically valid. Node/geometry and topology (GT)-polygon/chain
relationships are collected or generated to satisfy topological edit
requirements. These requirements include:
Complete chains must begin and end at nodes.
Complete chains must connect to each other at nodes.
Complete chains do not extend through nodes.
Left and right GT-polygons are defined for each complete chain element and
are consistent throughout the extract process.
The chains representing the limits of the file are free of gaps.
The Census Bureau performed automated tests to ensure logical consistency
and limits of files. All polygons are tested for closure. Some polygons in
the TIGER/Line files may be so small that the polygon internal point has been
manually placed on a node that defines the polygon perimeter. These small
polygons have been detected, and corrections will be incorporated in the Census
TIGER data base in the future. The Census Bureau uses its internally developed
Geographic Update System to enhance and modify spatial and attribute data in
the Census TIGER data base. Standard geographic codes, such as FIPS codes for
states, counties, municipalities, and places, are used when encoding spatial
entities. The Census Bureau performed spatial data tests for logical consistency
of the codes during the compilation of the original Census TIGER data base
files. Most of the codes themselves were provided to the Census Bureau by the
USGS, the agency responsible for maintaining FIPS 55. Feature attribute
information has been examined but has not been fully tested for consistency.
Completeness_Report: Data completeness of the TIGER/Line files reflects the
contents of the Census TIGER data base at the time the TIGER/Line files (1995
version) were created.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
The information present in these files is provided for the purposes of
statistical analysis and census operations only. Coordinates in the TIGER/Line
files have six implied decimal places, but the positional accuracy of these
coordinates is not as great as the six decimal places suggest. The positional
accuracy varies with the source materials used, but generally the information is
no better than the established National Map Accuracy standards for
1:100,000-scale maps from the U.S. Geological Survey (USGS); thus it is NOT
suitable for high-precision measurement applications such as engineering
problems, property transfers, or other uses that might require highly accurate
measurements of the earth's surface. The USGS 1:100,000-scale maps meet national
map accuracy standards and use coordinates defined by the North American Datum,
1983. For the contiguous 48 States, the cartographic fidelity of most of the
1995 TIGER/Line files, in areas outside the 1980 census Geographic Base
File/Dual Independent Map Encoding (GBF/DIME) file coverage and selected other
large metropolitan areas, compare favorably with the USGS 1:100,000-scale maps.
The Census Bureau cannot specify the accuracy of features inside of what was the
1980 GBF/DIME-Files coverage or selected metropolitan areas. The Census Bureau
added updates to the TIGER/Line files that enumerators annotated on map sheets
prepared from the Census TIGER data base as they attempted to traverse every
street feature shown on the 1990 census map sheets; the Bureau also made other
corrections from updated map sheets supplied by local participants for Census
Bureau programs. The locational accuracy of these updates is of unknown
quality. In addition to the Federal, State, and local sources, portions of the
files may contain information obtained in part from maps and other materials
prepared by private companies. Despite the fact that TIGER/Line data positional
accuracy is not as high as the coordinates values imply, the six-decimal place
precision is useful when producing maps. The precision allows features that are
next to each other on the ground to be placed in the correct position, on the
map, relative to each other, without overlap.
Entity_and_Attribute_Information:
Overview_Description:
Entity_and_Attribute_Overview:
The TIGER/Line files contain data describing three major types of
features/entities;
Line Features -
1) Roads
2) Railroads
3) Hydrography
4) Miscellaneous transportation features and selected power lines and pipe
lines
5) Political and statistical boundaries
Landmark Features -
1) Point landmarks, e.g., schools and churches.
2) Area landmarks, e.g., Parks and cemeteries.
3) Key geographic locations (KGLs), e.g., apartment buildings and factories.
Polygon features -
1) Geographic entity codes for areas used to tabulate the 1990 census
statistical data and current geographic areas
2) Locations of area landmarks
3) Locations of KGLs
The line features and polygon information form the majority of data in the
TIGER/Line files. Some of the data/attributes describing the lines include
coordinates, feature identifiers (names), CFCCs (used to identify the most
noticeable characteristic of a feature), address ranges, and geographic entity
codes. The TIGER/Line files contain point and area labels that describe
landmarks features and provide locational reference. Area landmarks consist of
a feature name or label and feature type assigned to a polygon or group of
polygons. Landmarks may overlap or refer to the same set of polygons.
The Census TIGER data base relates information to points or 0-cells, lines or
1-cells, and polygons or 2-cells. The number preceding the cell identifies the
dimensionality of the objects; for instance, a line segment has a single
dimension, length. Each of these objects build on the others to form
higher-level objects. The 0-cells form the end points of 1-cells. The 1-cells
connect at 0-cells and form closed figures that partition space into polygons or
2-cells.
The spatial objects in TIGER/Line files embody both geometry (coordinate
location and shape) and topology (the relationship between points, lines
objects, and polygons) and therefore belong to the "Geometry and Topology" (GT)
class of objects in the SDTS. In the SDTS, nodes represent point objects
(0-cells) that identify the start and end position of lines or 1-dimensional
objects (1-cells) called chains. The chains in the TIGER/Line files are
complete chains because they form GT-polygon boundaries and intersect other
chains only at nodes. Topological chains that do not contain polygon
information are network chains used to form GT-rings. Data users may choose not
to use GT-polygon or geographic entity codes and consider the TIGER/Line files a
source of network chain data.
The TIGER/Line files contain point landmark data that are not included in the
Census TIGER data base topology. Point landmarks are entity points that mark
the location of points of interest and are not connected to complete chains or
GT-polygons. A polygon identification code is used to link a landmark to a
GT-polygon.
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