Question: what is a wb-50 truck?
Answer: The WB-15 [WB-50] design vehicle has a 13.0-m [42.5-ft] trailer. This trailer size, or similar trailers with lengths of 12.2 m [40 ft] or 13.7 m [45 ft] was quite common prior to the 1982 STAA. ... The WB-19 [WB-62] design vehicle is a tractor-semitrailer with a 14.6-m [48-ft] trailer.