Red Hazard

Fatal Turns – Rear-Wheel Differentials of Dump Trucks and Tractor-Trailer Trucks

In Taiwan, there is an average of 800 dump-truck related accidents each year. The driver seats of large-sized trucks such as dump trucks and tractor-trailer trucks are positioned high above, which allows the drivers to see far into the front, therefore, in general, these trucks are less likely to run into people or objects that are in front of them. However, even with rear-view mirrors, there are blind spots that cannot be seen on both the left and right sides. If pedestrians or motorcycles fall into this range, the truck drivers may not be able to see them at all. Even after impact occurs, the drivers of the trucks may not feel a thing. Furthermore, it is often even more dangerous when the trucks are turning. When large trucks turn, their front wheels are the wheels that actually turn, while their rear wheels slowly turn in-place, forming a fan-shaped cutting angle. The above-described blind area in the drivers’ view plus the rear-wheel differential form a black hole of death in which many accidents occur. Therefore, most truck accident fatalities occur at the rear wheels of trucks.

What is the rear-wheel differential?


Large-size trucks are most dangerous when they turn because their bodies are so long. Their turn radiuses increase with the lengths of their bodies. This is especially true for dump trucks and tractor-trailer trucks. Therefore, if pedestrians waiting by the road are not careful, they could get run over by the rear wheels of these trucks even if the front wheels have already rolled past them.

Red Hazard Indicator Lights


The Red Hazard Safety Indicator Lights are installed in front of the rear wheels of large-scale tractor-trailer trucks to alert pedestrians and small cars near the sides of the trucks. When the trucks are turning, these indicators will issue warning sounds. In addition, the indicators lights also project red light onto the areas that the rear wheels will roll over, informing pedestrians around the truck to stay clear of those dangerous areas.