How to enter value of radius of curve in the software

please suggest how to enter radius of the curve of the road in this VIDA software in view of 20-30 percent fatalities occurring due to ROR(run off road), head on collision due to poor radius

Horizontal curvature is coded as very sharp (approx R<200m), sharp (approx R 200-400m), moderate (approx R 400-800) and straight or gentle curve (approx R>800m). You also need to code quality of curvature among other road attributes to get Star Rating. Please refer the iRAP Coding Manual available here. You can use Star Rating Demonstrator to generate Star Rating for a given road site. For detailed instructions on how to use Demonstrator you can take this free training course Introduction to iRAP available here.