17/8/2016 · HL-93 is a type of theoretical vehicular loading proposed by AASHTO in 1993. It isCustom as the design loading for highway structures in USA and other countries where AASHTO code is followed. AASHTO HL-93 vehicular live load is a combination of three different loads, HL-93 Design Truck (formerly, HS20-44 Truck) HL-93 Design Tandem