Jump to main content.

Southern California Roads Metadata Image of Southern California Study Area



    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.
    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
    U.S. Department of Commerce
    Bureau of the Census
    Geography Division
    Washington, DC
Data Processor:
    Ed Evanson
    Lockheed Martin Environmental Services
    1050 E. Flamingo Road, Suite E120
    Las Vegas, NV 89119
Data Provider:
    Dan Heggem
    U.S. Environmental Protection Agency NERL
    P.O. Box 93478
    Las Vegas, NV 89193-3478
    Wessex, roads, highways, streets, transportation, Southern California, 
    Pilot Study Area
Revision Number:
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.                
    Southern California data browser
Date of metadata entry/update:
No Publication Information Available
No File Security Information Available
Cloud Cover:
    Not applicable
    Arc/Info 7.2
Operating System:
Path Name:
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
    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:  
Update Frequency:
    As needed

             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
Fuzzy   =                40.300 N          Dangle  =                 0.000 N
                               COVERAGE BOUNDARY
Xmin =              -357114.180            Xmax =                45882.137
Ymin =              3399735.963            Ymax =              3658714.160
The coverage has not been Edited since the last BUILD or CLEAN.
                          COORDINATE SYSTEM DESCRIPTION
Projection               ALBERS
Datum                     NAD83
Units                    METERS             Spheroid                GRS1980
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

Annotation Name:

ATTRIBUTE LISTING FOR: sca_roadsa83.aat

    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      -                        -

FGDC Content Standards for Digital Geospatial Metadata
FGDC Standards Version 6/98 / metadata.aml ver. 1.3 5/21/99


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 

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).

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.
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.

The TIGER/Line files contain data describing three major types of 
Line Features -
 1) Roads
 2) Railroads
 3) Hydrography
 4) Miscellaneous transportation features and selected power lines and pipe 
 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

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 

Southern California Home | More Databrowsers
Landscape Ecology | Environmental Sciences | Exposure Research | Research and Development

Local Navigation

Jump to main content.