AASHTO 3.24.3 (17TH ED) considers Case A and Case B for slab design.
Case A - Main Reinf. -Traff. Perpendicular
Case B - Main Reinf. - Traffic Parallel
AASHTO 3.24.6 (17th Ed.) uses proportioning of load for reinf in either direction.
3.24.6 gives way lesser amount of reinf versus 3.24.3...