The 13 Controlling Criteria

As discussed in Chapter 1, FHWA has identified 13 design criteria as having substantial importance for the safe and efficient operation of highways.  A formal design exception is required if these controlling criteria are not met on the NHS: 

1. Design Speed

2. Lane Width

3. Shoulder Width

4. Bridge Width

5. Horizontal Alignment

6. Superelevation

7.  Vertical Alignment

8. Grade

9. Stopping Sight Distance

10. Cross Slope

11. Vertical Clearance

12. Lateral Offset to Obstruction

13. Structural Capacity

Exceptions to non-controlling criteria should also be identified, justified, and documented, taking into consideration the effect of any deviation from design criteria on safety.  The project files should include this information.

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