Real-World Performance of Longitudinal Barriers Struck by Large Trucks

Very little is known about the real-world performance of traffic barriers when subjected to impacts by large trucks. This study investigated real-world impacts of large trucks into traffic barriers to determine barrier crash involvement rates, the impact performance of barriers not specifically designed to redirect large trucks, and the real-world performance of barriers specifically designed for large trucks. Data sources included the Fatality Analysis Reporting System (2000 to 2009), the General Estimates System (2000 to 2009), and the Large Truck Crash Causation Study (155 in-depth crashes of large trucks into barriers). Impacts of large trucks into longitudinal barriers constituted 3% of all police-reported impacts into longitudinal barriers and roughly the same proportion of barrier fatalities. A logistic regression model predicting barrier penetration showed that the risk of a large truck penetrating a barrier increased by a factor of 6 for impacts with barriers designed primarily for passenger vehicles. Although barriers specifically designed for impacts by large trucks performed better than barriers not specifically designed for impacts by heavy vehicles, the penetration rate of the former was 17%. This penetration rate is of concern, because barriers used for higher test levels are designed to protect other road users, not the occupants of large trucks. Barriers not specifically designed for impacts by large trucks prevented penetration by a large truck approximately half the time. This finding suggests that adding costlier barriers that meet higher test levels may not always be warranted, especially on roadways with lower truck volumes.