This articles gives a brief about the .wid file required while curve widening.
The curve widening in OpenRoads requires a .wid file, that has to be written manually depending upon the Standards or user requirement. The columns required in the file are as below:
Rad : Radius of the curve
Wi : Widening Width to be applied to the inner curve
Li : Transition Length from current position to the widened width for the inner curve
Wo : Widening width to be applied to the outer curve
Lo : Transition length from the current position to the widened width for the outer curve.
For a condition like curve without transition, you can apply "Percent transition on tangent" in the "Create Curve Widening" dialog box directly.
Attached is a sample .wid file, this file can be edited as per the project requirement.