Exploring the Influencing Factors and Formation of the Blind Zone of a Semitrailer Truck in a Right-Turn Collision

Abstract

The blind zone that accompanies the right-turn process of semitrailer trucks is a major cause of crashes and the high fatality of vulnerable road users (VRUs). Understanding the relationship between the blind zone and right-turn collisions will play a positive role in preventing such accidents. The purpose of this study was to investigate the formation of right-turn blind zones for semitrailer trucks and to determine the factors (turning speed, turning radius, and collision position) influencing the severity of accidents through real-world vehicle tests and PC-CRASH simulation. The results show that the calculation model of the inner wheel difference blind zone established for semitrailer trucks can provide more accurate estimation than the model for rigid trucks, due to the consideration of a virtual third axle between the tractor and the trailer. On the other hand, the PC-CRASH simulation test indicates the turning speed and turning radius directly affect the scale of the inner wheel difference blind zone, and larger blind zone and encroachment on adjacent lanes increase the potential for collision. Moreover, the difference in collision position is closely related to whether the rider suffers a secondary crush. Front position is more likely to cause the cyclist to be crushed. For further analysis, the long-term interaction between the blind zones resulting from the right rearview mirror and the inner wheel difference also increases the risk during a right turn. Therefore, reducing the blind zone in the right-turn process is the key to improving right-turn safety for semitrailer trucks and VRUs.

A semi-trailer truck right-hook turn blind spot alert system for detecting vulnerable road users using transfer learning

“…Based on the CAD design and the potential camera placements (Figure 4) of the vehicle, it was determined that an attachment of the camera on the right rear-view mirror would be able to (a) perform the strongest in detecting oncoming cyclists (Figure 13: A), and (b) cover a semi-trailer truck's blind spot most effectively during a right-hook turn at an intersection as outlined by Wang et al (2022). Fur-thermore, the system's active audible and visual alerts address the concerns for driver attention described by Jannat et al (2020) [4].…”

“…Semi-trailer trucks have large blind spot zones on the vehicle's left, right, front, and rear. The right-hand blind spot poses the most danger to vulnerable road users (VRUs) -cyclists, pedestrians, moped riders, and motorcyclists-especially when making right turns [5]. Blind spots are a leading cause of truck-cyclist incidents-they account for 45% of all collisions between bicycles and trucks [5].…”

“…The right-hand blind spot poses the most danger to vulnerable road users (VRUs) -cyclists, pedestrians, moped riders, and motorcyclists-especially when making right turns [5]. Blind spots are a leading cause of truck-cyclist incidents-they account for 45% of all collisions between bicycles and trucks [5]. Additionally, semi-trailer trucks are disproportionately involved in more severe cyclist collisions compared to other vehicles [1].…”

“…When a semi-trailer truck makes a right turn, the blind spot from the right rearview mirror increases as the view is blocked by the trailer's body. This makes turns especially dangerous because VRUs in this blind spot zone cannot be detected and face a high risk of collision and fatality [5] (Figure 2).…”