Originally Posted by Redfire

While trailers are effected by crosswinds (either naturally occurring or from another vehicle) it is the drivers responsibility to maintain control over the trailer they are pulling. The main reason a trailer sways is because it is improperly loaded or the tow vehicle is not large enough or does not have the proper equipment, another common problem is having the hitch at the wrong height. If a trailer is equipped with brakes you can quickly regain control just by applying light pressure to the trailer brake controller located inside the tow vehicle. If the trailer is fairly large/heavy the tow vehicle should be equipped with weight distribution and sway control to aid in keeping the trailer on the same path as the tow vehicle. This is not just for the safety of cyclist but also other vehicles on the road as well as the people located in the tow vehicle.