DATABASE NAME

     ST_2M:  1:2,000,000 base map scale State Boundaries

DATABASE DESCRIPTION

     1:2,000,000 base map scale state boundaries for use with
     1:2,000,000 network databases.

ORIGINATING AGENCY

     Federal Railroad Administration

AGENCY RESPONSIBLE FOR MAINTAINING DATA

     Bureau of Transportation Statistics

CONTACT

     National Transportation Atlas Databases
     Bureau of Transportation Statistics
     U.S. Department of Transportation
     Washington, DC  20590
     (202) 366-DATA
     Internet:  info@bts.gov

SOURCE

     1:2,000,000 USGS Digital Line Graphs supplemented by editing
     performed by the Federal Railroad Administration

ACCURACY

     1,200 m (0.75 mi) root-mean square positional accuracy

TYPE OF GIS DATABASE

     Line database with nodes and links

FILES/SIZE/NUMBER OF RECORDS

     Two ASCII files

     1)   st_2m.pnt      node file contains point locations
     2)   st_2m.lin      link file contains link attributes and
                         shapes

     Approximate size of files:    3,076,000 bytes
     Approximate number of nodes:  2,300
     Approximate number of links:  2,350

FILE STRUCTURE

     The files are ASCII-comma delimited.  Character fields are
     enclosed in quotation marks.

     The Node File

   FIELD  ITEM                TYPE      REMARKS

     1    Node ID             Num       Unique node number
     2    Longitude           Float     Longitude of node
                                        (decimal degrees with
                                        explicit decimal
     3    Latitude            Float     Latitude of node (decimal
                                        degrees with explicit
                                        decimal
     The Link File

   FIELD  ITEM                TYPE      REMARKS

     1    "From" node number  Num       The Node ID in st_2m.pnt
     2    "To" node number    Num       The Node ID in st_2m.pnt
     3    Link ID             Num       Unique Id number
     4    Length              Float     Length of link (mi)
     5    Direction           Num       Always 0
     6    State left          Num       State postal code on left
                                        side of link
     7    State right         Num       State postal code on
                                        right side of link
     8    Code                Num       
     9    N                   Num       Number of following
                                        Longitude-Latitude pairs
                                        in decimal degrees
     10   Longitude           Float     Explicit decimal} First 
     11   Latitude            Float     Explicit decimal} pair

          Long-Lat pairs      Float     Shape points of the link
          repeat N-2 times    Float     in pairs of long-lat

          Longitude           Float     Explicit decimal}  Final
          Latitude            Float     Explicit decimal}  pair

DISCUSSION

     A 1:2,000,000 state boundary file was included to provide a
     boundary reference file for use with the 1:2,000,000 network
     files.  Because this boundary database is smaller in size
     than the 1:100,000, it can be drawn faster.

     This database includes only the continental United States.

     This database was extracted as a line database for viewing
     reference only and would require additional work to be
     converted to an area database.  See individual GIS packages
     for instructions on how to do this.