Looking in the 4th Edition AASHTO LRFD - Under 5.5.3.2, trying to figure out how to apply this. The way I interpret it is to calculate the stress in the reinforcing steel resulting from the fatigue load specified in 3.6.1.4 @ 1/3 of the span from the maximum moment and compare to the applicable equation listed in this section. Is this right? Also, seems that this same stress is part of fmin (combined with other stress as indicated). Thanks for the help!