What are the average size of a tractor trailer?

Typical length for five axle unit consisting of a sleeper berth tractor and single 48 - 53 ft. trailer will be between 67 and 77 ft. in total length. With a Kenworth W900L and 53 ft. stepdeck, I totaled 77 feet in length. A typical fleet truck will have a wheelbase between 210 and 240 inches. In some states, 57' trailers are allowed to be used without requiring a permit, adding another four feet to the total length of the truck.