6.1 Introduction to general architecture

ASAM OpenDRIVE data is stored in XML files with the extension xodr. Compressed ASAM OpenDRIVE files have the extension xodrz (compression format: gzip).

The ASAM OpenDRIVE file structure conforms to XML rules; the associated schema file is referenced in the XML. The schema files for the ASAM OpenDRIVE format can be retrieved from Section "Deliverables".

Elements are organized into levels. Elements with a level greater than zero (0) are children of the preceding level. Elements with a level of one (1) are called primary elements.

Each element can be extended with user-defined data. This data is stored in user data elements.

All floating-point numbers used in ASAM OpenDRIVE are IEEE 754 [12] double precision floating-point numbers. To ensure accurate representation of floating-point numbers in the XML representation, implementations should use a known correct accuracy preserving minimal floating-point printing algorithm (for example [13], [14]) or ensure that 17 significant decimal digits are always produced, for example using the "%.17g" ISO C printf modifier. Importing implementations should use a known correct accuracy preserving floating-point reading algorithm (for example [15]).