Transporting Equipment with Trailers
Lots of equipment such as boats and yachts are hauled using trailers. Multiple-trailer
trucks have more handling problems than single-trailer trucks. In general,
the additional connection points contribute to greater instability, which
can lead to jackknifing, overturning, and lane encroachments. A study
in Washington State found that doubles (tractors pulling two trailers)
were two to three times as likely as other rigs to be in crashes, and
a study in Indiana found that doubles showed increased crash risk on roads
with snow, ice, or slush. One mitigating factor for the risk of a crash
of a double trailer may be that they should be operated by drivers with
good safety records.
Single-trailer rigs can stretch up to 65 feet in length from the kingpin–where
the trailer joins the tractor–to the rear axle. And multiple-trailer
rigs can stretch up to 75 feet from kingpin to rear axle.