For AASHTO LFD, design of shear is carried out according to AASHTO specifications. However, if torsion is present in the section along with shear, torsion design is based on ACI 318-95 specifications (as suggested by AASHTO Standard specifications).

In AASHTO Standard, when the torsion is less than the limiting torsion, the maximum spacing is based on Art. 8.19.3. However, when torsion is more than the limiting value, program also checks the spacing as per ACI 11.6. For AASHTO Standard, the program reports the total longitudinal steel required for torsion (Alt). Users may reduce this amount by provided steel in excess of required steel already present at that section.