county attributes table structure

The county attributes table contains key freight modelling attributes of each county within the modelled region, including the number of freight points of entry, the distance to the nearest freight points of entry, and the length of transportation infrastructure. It is used by the CRISTAL freight model for high-level movement synthesis.

Table Structure

Field	Type	NULL allowed	Default Value	Foreign key	Description
county*	INTEGER	NO			The unique identifier of the county
num_railports	INTEGER	NO	0		The number of railports in the county
num_airports	INTEGER	NO	0		The number of airports in the county
num_waterports	INTEGER	NO	0		The number of waterports in the county
truck_distance_to_railport	REAL	YES	0		The truck distance to the nearest railport
truck_distance_to_waterport	REAL	YES	0		The truck distance to the nearest waterport
truck_distance_to_airport	REAL	YES	0		The truck distance to the nearest airport
highway_length	REAL	YES	0		The length of highways in the county
railway_length	REAL	YES	0		The length of railways in the county
waterway_length	REAL	YES	0		The length of waterways in the county
transportation_estabs	REAL	YES	0		The number of transportation establishments in the county
wholesale_estabs	REAL	YES	0		The number of wholesale establishments in the county
retail_estabs	REAL	YES	0		The number of retail establishments in the county
area_size	REAL	YES	0		The area size of the county

(* - Primary key)

The SQL statement for table and index creation is below.

CREATE TABLE IF NOT EXISTS "County_Attributes" (
    "county"                      INTEGER NOT NULL PRIMARY KEY,
    "num_railports"               INTEGER NOT NULL DEFAULT 0,
    "num_airports"                INTEGER NOT NULL DEFAULT 0,
    "num_waterports"              INTEGER NOT NULL DEFAULT 0,
    "truck_distance_to_railport"  REAL DEFAULT 0,
    "truck_distance_to_waterport" REAL DEFAULT 0,
    "truck_distance_to_airport"   REAL DEFAULT 0,
    "highway_length"              REAL DEFAULT 0,
    "railway_length"              REAL DEFAULT 0,
    "waterway_length"             REAL DEFAULT 0,
    "transportation_estabs"       REAL DEFAULT 0,
    "wholesale_estabs"            REAL DEFAULT 0,
    "retail_estabs"               REAL DEFAULT 0,
    "area_size"                   REAL DEFAULT 0
);