WB is the designation for a semitrailer vehicle (tractor and trailer). The number that follow refer to the wheelbase, measured from the front wheels of the truck tractor to the most rear wheels of the trailer. There are also units with double or triple trailers, desidnated with a D or T after the number. AASHTO's green book has dimensions of various vehicles and their turning movements. Do a web search and you'll probably be able to find the information from a variety of sources. FHWA might be a source, or your state highway department. AASHTO does not show either tankers or automobile carriers, but I would try to design around a WB-67, which is the largest semi-trailer rig. Delivery trucks would likely be designated as single-unit (SU) vehicle (no trailer), which has different turning dimensions than a semi-trailer.
A designer would typically use a copy of a turning movement diagram on a clear sheet to overlay the plans to check for conflicts. There are tables which give minimum turning radii for various vehicles, but this isn't always enough to design from.