Purpose: Prevents AASHTO truck from being considered as a possible alternative loading in the permit lane.
--> Given in girder system input
A given permit loading is placed in the lane nearest to the girder for which live effects are being determined. By default the AASHTO (or HL93) loading also is applied as a loading in that lane, and the governing effects from the two types of loading are used. Use of this condition causes the permit loading to be the only loading considered for that lane.