Road data is defined in an RDF file as shown in the figure above. The file is written in text format and contains keywords and values. The keywords related to a unit system are used for unit conversion when a value is converted into the model unit system. The table below describes the [UNITS] block of the RDF file format.
Figure 6.62: Keywords in the RDF file
| Keyword | Description | Dimension |
| LENGTH |
Use to set the length unit system. The available length units are as follows. Micrometer = 'um' Millimeter = 'mm' Centimeter = 'cm' Inch = 'inch' Meter = 'm' or 'meter' Kilometer = 'km' Mile = 'mile' |
N/A (Character) |
| FORCE |
Use to set the force unit system. The available force units are as follows. MilliNewton = 'mN' Newton = 'N' KiloNewton = 'kN' |
N/A (Character) |
| ANGLE |
Use to set the angle unit system. The available angle units are as follows. Radian = 'rad' or 'radian' or 'radians' Degree = 'deg' or 'degree' or 'degrees' |
N/A (Character) |
| MASS |
Use to set the mass unit system. The available mass units are as follows. Miligram = 'mg' Gram = 'g' Kilogram = 'kg' Ton = 'ton' |
N/A (Character) |
| TIME |
Use to set the time unit system. The available time units are as follows. Millisecond = 'ms' Second = 'sec' |
N/A (Character) |