# OpenDRIVE Importer¶

ASAM OpenDRIVE defines an open file format for the precise and logical description of road networks (see www.opendrive.org for more information).

The OpenDRIVE format provides a common basis for describing road networks using XML syntax. The data stored in an OpenDRIVE file describes the geometry of roads as well as associated features such as lanes, markings, signposts, signals, junctions, crosswalks, buildings, and more.

The Aimsun Next OpenDRIVE importer enables you to import OpenDRIVE (extension: XODR) files.

To import an OpenDRIVE file:

1. Select File > Import > OpenDrive File. The Select One or More files dialog opens.

2. Navigate to the XODR file you want to import.

3. Click Open to import and load the file.

## The relation between OpenDRIVE objects and Aimsun Next objects¶

Every OpenDRIVE file contains information about the road network as already mentioned. Each road is described independently in terms of type, information about lanes, width of lanes, etc. They contain respective link information (i.e. predecessor–successor information) about connections to other roads in the same network. Also, junctions help to resolve potentially ambiguous predecessor–successor relationships. Signals and signs are defined per road. Finally, controllers provide a means of grouping dynamic signals.

The track coordinate system and local coordinate system information provided in the OpenDRIVE file is converted by Aimsun Next to an inertial coordinate system (x,y,z). All roads comprise a reference line which defines the basic geometry. The various geometrical features supported are: straight line, spiral, curve, cubic polynomial, and parametric cubic curves.

### Nodes and turns¶

Aimsun nodes are created by using link and/or junction information. As a result, all possible turns are created.

### Lanes¶

Aimsun lanes are created using the laneSection information provided in the Open DRIVE XML file.

Road segments are created by using lane information and the predecessor–successor information.

### Crosswalks¶

Objects in the OpenDRIVE file with the type crosswalk or roadMark are imported into the Aimsun model as pedestrian crosswalk areas.

### Buildings¶

All objects in the open drive file with type building are imported as building artefacts that can be used as obstacles for pedestrians as well as for decoration.

## Limitations of OpenDRIVE imports¶

• Importing road objects (VMS, detectors) and traffic signals is not yet supported.
• Lanes with widths that vary are not supported. The width is set to the average width found within the lane.
• Roads with lane-type information specified as driving, tram, biking, and reserved lane are supported but any unsupported lane types in OpenDRIVE are not imported into Aimsun Next.
• Importing controllers is not yet supported.