Format: ALERT-C Location Tables
Simplified road network description according to CSN EN 14819-3, consisting of logically interconnected elements represented by nodes or other important points of the road network, sections of the road network and areas. These elements are assigned unique identifiers in the location table, which are then used to describe the location of a traffic event. Both the provider and the subscriber must have these tables in order to assign location to the received traffic information.
ALERT-C location tables are provided in several different formats:
- TMC Location Table Exchange Format (version 2.3) - the main format for location tables exchange. The format describes the minimum information that is needed to define the location tables. It can be extended by other information that is not subject to the TISA certification process. The format structure includes: 1 text file with metainformation, and 23 text files / tables that represent a standard version of LT.
- TXT format - consists of 4 files, each containing information about a certain set of data from the location table (points, streets and roads, communication segments, administrative areas). These files are maintained in the basic text format in the file format with the extension .txt in the encoding of the Windows-1250 character set. File names are chosen to fit their content as closely as possible.
- ESRI format - consists of 4 file groups, each group contains information about a certain set of data from the location table (points, roads and streets, communications segments, administrative areas). The file groups are created in ESRI products, which carries a certain file overhead. Spatial expressions have points and linear location table elements in S-JTSK or WGS-84.
- Google Earth format - This is a single Google Earth file (extension .kml). The file contains structured information viewable on the world map in Google Earth, except for text information that includes a point representation. A spatial file of this format is available in the WGS-84 coordinate system.