A semitrailer accident occurs when there is an accident between the semi-trailer and another vehicle or person. Sometimes there will be no tractor involved, as if the semi-trailer was parked incorrectly, collapsed, or tipped over on another vehicle or person. Other times, the semi-trailer is the object that causes the accident, and there is no damage to the tractor (the front portion of the semi-truck).
Semitrailers also can cause accidents when they are improperly hooked up. When a trailer is improperly hooked up, there are a number of problems that can lead to a semitrailer accident. Improper attachment of a semitrailer can make the brake lights and lighting on the sides of the trailer fails to function. This leads to poor visibility, and surprises other vehicles when the semi-truck slows, but no brake lights indicate this slowing to other drivers. This causes vehicles to rear end the semitrailer.
Semitrailer accidents can also occur when the trailer has unordinary equipment. Sometimes equipment on the semitrailer can be unbalanced, prone to movement, or even come unsecured while in motion.
Unbalanced: An unbalance in the semitrailer can make it impossible to steer. Most notably are the semitrailers that haul liquid. When the liquid semitrailer is empty or full, the trailer behaves normally. However, if the semitrailer is half full of liquid, the trailer is extremely prone to roll overs, tipping over, jack-knifing, and losing control, because of the high center of gravity of the trailer, and the uneven weigh distribution after the trailer starts moving.
Prone to movement: When semitrailers are stacked improperly, or there are two or even three semitrailers, the trailers are considered prone to movement. This means that the trailers are more likely to move inconsistently with the way the truck driver expects. Improperly stacked loads will shift, and will force the semi-truck driver to correct or over-correct. Any inconsistent movement is likely to cause a semitrailer accident. When there are two or three semi-trailers, they function with different pivot points, causing the trailers to veer out of lane on turns, and be very difficult to back up in a straight line.
Unsecured Movement of the Semitrailer: When semitrailers have their load shift, move, or have an apparatus that comes unhinged, the resulting movement can force the driver of the semitrailer to be unable to control his vehicle. The unsecured movement on the semitrailer is unexpected and usually occurs when the semitrailer is in motion, and often around a turn. These types of movement, sometimes accident causing movement can be avoided with proper pre-trip and post-trip inspections. The inspection cannot prevent unsecured movement, but it can reduce the risk of the movement as much as possible.