The semi truck’s tractor and trailer have a combined length of about 70 feet. A typical highway lane width is about 12 feet. As one might expect, making a u-turn with a semi truck on a two lane highway isn’t easy. It’s also dangerous because a semi truck takes a long time to execute the maneuver and blocks both lanes. Additional reasons semi truck u-turns are dangerous include:
Unlike a car that permits a 360 degree view when the driver turns her head, the semi truck’s trailer blocks the truck driver’s view and therefore reduces his situational awareness. This may force the driver to rely on the traffic to slow down and stop for his benefit. This is dangerous because motorists aren’t always 100 percent focused on their driving and often drive too fast.
Low Visibility Conditions Heighten the Danger
The risk of a collision increases in low visibility conditions such as during the night, in fog, rain, or snow. If the truck is attempting the u-turn near a blind hill, corner, or other visual obstruction, the traffic has little reaction time for stopping. Poor traction conditions such as wet or snow-covered pavement worsen the problem.
Underride Collisions Are Common
Car collisions into semi trucks during a u-turn are often fatal. On a two-lane highway, a semi truck u-turn exposes the side of its trailer to both lanes of traffic. This may cause an underride collision, where the bottom half of the car goes under the trailer while its top half is sheared off. Bumpers, crumple zones, seat belts, and airbags will not protect the motorist.
Why Truck Drivers Make U-Turns
Truck drivers do u-turns for a variety of reasons. They may not have the time or inclination to look further down the road for a safe turnaround point. Another reason is when a low clearance overpass blocks their way. This may happen when the driver gets lost and goes off-route. Sometimes the driver makes a quick decision to try a short cut. Truck drivers may also use a GPS intended for the general driving public. These don’t provide truck specific information such as height clearances and weight limits.