[Lew Silverman]

Here's the posted regulation from the State of Michigan

http://www.michigan.gov/documents/Loads_dim_87014_7.pdf

Length of a combination of truck-tractor, semitrailer, and trailer or truck-tractor and 2 semitrailers or truck and semitrailer or trailer with or without load or pickup truck, semitrailer designed for recreational living purposes, and additional trailer or semitrailer (see exceptions) 65 feet

Interesting that you can tow a recreational (living quarters) trailer AND an additional trailer with a fifth-wheel equipped pick-up truck and be 75 feet in length with a special endorsement on your license.

Hope this helps!

Lew