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Aimsun Next Files

Document Files

Aimsun documents can be stored in the following format:

  • ANG File: A compressed Aimsun document in a proprietary binary format. Example: network.ang

An old format ANZ file, used up to release 8.1, will still be read but the format was deprecated in Aimsun Next 8.2. Example:

When saving a document, Aimsun Next will create several backup files resulting in three different versions of the document:

  1. The current document that is being edited, with ANG extension. If the save operation fails, the file will contain partial information.
  2. The document with the version of the immediately previous saved document, with extension ANG.OLD. This file is updated every time the document is saved during the session, so it contains the next-to-last version of the document.
  3. If this is the first time this file is saved since it was loaded into Aimsun Next, in addition to the OLD file, a copy of the document with extension SANG will be saved. This file will not be updated at any point during the session, so it will contain the version of the file immediately after loading it into Aimsun Next for the first time.

Another backup file is the Auto Save option that will save the document with a ANG.AUTO extension at every time interval specified by the user in the Project Preferences.

Data Files

Aimsun Next will save files with data about route choice, recorded data from the simulation for replay or for data analysis, log files from external applications and temporary files required as Aimsun Next is run.

These files are:

  • Paths Files: These APA files contain path information and form the data in a Path Assignment Object. By default, they are located in the same directory as the Aimsun document that refers to that Path Assignment Object, but an alternate location can be specified by the user.
  • Results Databases: These files are created as an experiment or a replication is run and hold the results of the simulation. The format of the file, and hence its file extension, depends on the database format selected for the entire project or for each scenario. These files are documented in the Storing Simulation Results Section and by default are located in the same directory as the Aimsun document but an alternate location can be specified by the user.
  • Replay Files: A microsimulation can be recorded as it runs and subsequently replayed, stepping forwards and backwards in time. The data required to do this is stored in files named rec_xxxx.arf" file in the same directory as the Aimsun document, where xxxx is the ID of the replication. These files can be deleted if they are no longer required.
  • Log files: These files are generated by Adaptive Control Interfaces and usually have a TXT or a .log extension. They are intended to be used for debugging purposes and are not required by subsequent simulations.
  • Temporary Files: These files are generated by Aimsun Next as it runs and generates a Path Assignment Object. They are held in the system temporary file store, on a Windows operating system this is C:/Users/"user"/AppData/Local/Temp. These files can be deleted once the Path Assignment Object has been generated, they are not required as it is used.