Are multiple-trailer trucks more likely to crash than single-trailer trucks?
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. But the relationship between multiple-trailer trucks and crash risk isn’t firmly established. A study in Washington state found doubles (tractors pulling two trailers) were two to three times as likely as other rigs to be in crashes, but a study in Indiana found doubles didn’t show increased crash risk except on roads with snow, ice, or slush. Doubles often are operated by drivers with good safety records working for large companies with active safety programs.