Prediction of Bridge Component Ratings Using Ordinal Logistic Regression Model
Table 1
Condition ratings used in the National Bridge Inventory (NBI).
Code
Meaning
Description
9
Excellent
As new
8
Very Good
No problems noted.
7
Good
Some minor problems.
6
Satisfactory
Structural elements show some minor deterioration.
5
Fair
All primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
4
Poor
Advanced section loss, deterioration, spalling or scour.
3
Serious
Loss of section, deterioration, spalling or scour has seriously affected primary structural components. Local failures are possible. Fatigue cracks in steel or shear cracks in concrete may be present.
2
Critical
Advanced deterioration of primary structural elements. Fatigue cracks in steel or shear cracks in concrete may be present or scour may have removed substructure support. Unless closely monitored it may be necessary to close the bridge until corrective action is taken.
1
Imminent Failure
Major deterioration or section loss present in critical structural components or obvious vertical or horizontal movement affecting structure stability. Bridge is closed to traffic but with corrective action may put back in light service.
0
Failed
Out of service, beyond corrective action.
Source: United States Department of Transportation. Recording and Coding Guide for the Structure Inventory and Appraisal of the Nation's Bridges. Washington, D.C., 1995, page 38.