Q-Traf

Q‑Traf Input File Structure

Input Files

The traffic modelling uses 3 types of files (all of which can be opened with a text editor) :

  • QGis layers (exported as *.geojson)
  • matrix files (*.csv)
  • a project file (*.qtr)

All these files can be opened with a text editor.

The necessary files are :

  • a “links” file, or multiline QGis layer (in geojson format). This is the “road network”.
  • a “zones” file, or point QGis layer (in geojson format)
  • the trips matrices files, “.csv” files
  • the project file (*.qtr)

There could be 2 optional QGIS layers :

  • a “Parks” file, or point QGis layer
  • a “Traffic counts” file, or point QGis layer

Here are the structure of these files :

QGIS Input Layers (*.geojson)

Links files - Fields of the QGIS vector layer
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Zones file (point QGis layer)

Zones files - Fields of the QGIS vector layer
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Optional QGIS layers

Traffic counts (point QGis layer)

Traffic counts files - Fields of the QGIS vector layer
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Parks file (point QGis layer)

Parkings files - Fields of the QGIS vector layer
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Matrix file

There can be a matrix file for each combination : {scenario, vehicle type, time period} (see below).

Matrix csv file
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Matrix file naming rules

You can NOT choose the matrix files names ; the names of the trips matrix files are not left to the user’s choice, but are defined by the software according to the project parameters. The names of the matrix files are composed of the names of : the project name + the scenario + the vehicle type + the time period. The naming rules are as follows :

The naming rules of the trips matrix files

For example, a common case is to have 2 different scenarios, with 2 different road networks (with and without a bridge for example), but using the same matrices (same date, same routes), with 2 types of vehicles. There will then be 2 matrix files.

The other common case is to have 2 different scenarios, with the same road network but different trips (let’s say for 2 different time horizons), with 2 types of vehicles. There will then be 4 matrix files.

And in the case with 3 scenarios, each with a different set of matrices, and 2 types of vehicles, 6 matrices files will be used.

While the software searches for all possible combinations of matrix names, not all of them are always necessary, and the software does not create errors if it does not find all of them. This structure, which can sometimes be complicated, allows for a higher number of variations.

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