How Some Trailers Pose an
Extra Risk on the Road

By Tim Becker —

Twins, double-pups, wiggle wagons, b-trains, turnpike doubles – they come in all different combinations and have a variety of names in trucker lingo.

Still, we all know what they are. We’ve driven cautiously past them with our hands suddenly fixed at ten and two like we’re back in drivers ed. They’re the trucks with two trailers attached, one behind the other. The nicknames are just trucker-speak to differentiate the length and configuration of the trailers they’re hauling. For regular drivers, they’re just called double trailers, and they can be very dangerous.

The increased risk of driving double trailers has been common knowledge for decades. In fact, in 1988 a Washington State study found that double trailers were two to three times more likely to be involved in a crash than other trucks.

Double trailers are more dangerous because they exaggerate the safety risks posed by regular commercial trucks. By adding a trailer, drivers increase the size of their blind spots, braking distance and the surface area of their vehicle, which makes them more susceptible to strong winds.

They also decrease the already small amount of maneuverability that a commercial truck has in the first place. The movement of a second trailer can be unpredictable and difficult to control for even the most experienced of truck drivers (hence the term ‘wiggle wagon’).

When doubles are involved in a crash it often involves more cars and affects more lanes of traffic. This is because the trucks have two articulation points. They tend to spread out further and take up more room thereby increasing the likelihood of subsequent crashes.

This quote was taken from Truckers Report, an online commercial trucking industry forum:

“I can tell you there’s no way in hell I’m pulling doubles. I’ve seen too many doubles flipped over, or scorpion tail a car next to them (when a rear trailer randomly whips to one side and slaps a car beside it like a scorpion tail) and to me, the risk isn’t worth it.”

Each state has different laws about which combinations of sizes are allowed on the road. For example, the largest configuration currently allowed in most states is two 28-foot trailers. Twin 33s (two 33-foot trailers being hauled by one cab) are allowed in only 12 states. But recently the trucking industry has attempted to change that.

Last year the trucking industry lobbied the federal government to force all states to allow twin 33s. A bill was almost passed that would have done just that, if it weren’t for Senator Roger Wicker of Mississippi, who urged fellow senators to remove the twin 33 mandate.

In addition to adding a dangerous amount of length to the ‘rig,’ twin 33s increase the weight that a truck can bear (by about 18 percent). More weight on one truck increases damages to the roads and bridges, which taxpayers, like you and me, have to pay to repair.

Another consequence of passing the law would have been an industry-wide shift in demand. More shippers would demand to have their freight hauled by twin 33s. By creating a new industry standard the law would invite an exponentially greater number of dangerous vehicles onto the nation’s highways.

In the end the Senate revised the bill, taking out the provision that legalized twin 33s across all states.

The trucking industry players who pushed for the law make up the Coalition for Efficient and Responsible Trucking (CERT). Members include FedEx, UPS and other major freight lines.

Laws concerning double trailers and other aspects of commercial trucking are not set in stone. As different parties push for changes, we can protect ourselves as drivers by staying up to date on movement within the industry.

One way to do that is by reading updates on this blog. More sources of information on commercial trucking law can be found below:


Tim Becker, a truck crash attorney with Dollar Burns & Becker and victim advocate.