Heavy truck aggressivity reduction: statistics, analysis, and countermeasures

Abstract

This document presents a study that (i) analyzed the causes of heavy truck aggressivity, (ii) evaluated their relative importance in terms of frequence and injury outcomes to occupants of light vehicles in crashes with trucks, (iii) derived detailed models relating collision factors to injury outcomes, and (iv) proposed and evaluated truck structural countermeasures for mitigating light vehicle injury in crashes with trucks. Two-vehicle truck/light vehicle crashes account for 65% of all truck crash involvements and 60% of fatal truck involvements. Crashes involving the truck’s front have the highest probability of a fatal or incapacitating injury. Collisions with the truck’s side account for about the same number of deaths or injuries but have a lower probability of injury. Injury counts and probabilities are also present for other crash configurations. Collision and injury models were derived to predict occupant injury outcomes from fundamental collision variables: mass, velocity, direction of travel, structural properties of colliding vehicles, and available restraint systems. Simulation results showed that reducing peak vehicle deceleration resulted in lower injury risk for most injury measures. Prevention of frontal underride, energy-absorbing truck structures, and deflection were evaluated as countermeasures. Reduction of up to 27%-37% in fatality counts are possible by preventing underride. Crushable structures of 2.6m would produce almost 25% reduction in fatalities. Deflection could reduce fatality from 46% to 72%, though these results only account for the impact with a truck, not any secondary collisions with other vehicles or roadside structures.