NBIS Ratings based on Structural Condition based on the worst condition seen in the field. Select the type of Superstructure, Substructure, Culvert, and so forth to rate. Then select the worst condition seen in the field and the app will provide you with the suggested rating of the element in question. If it is a critical condition, the app reminds you of what you need to do in such cases. Currently the app uses Illinois Department of Transportation (IDOT) ratings as part of the NBIS rating but we are looking to include more states and FHWA soon!