Evaluation of Drivers of Very Large Pickup Trucks: Size, Seated Height and Biomechanical Responses in Drop Tests 2023-01-0649

This study focused on occupant responses in very large pickup trucks in rollovers and was conducted in three phases.

Phase 1 - Field data analysis: In a prior study [9], 1998 to 2020 FARS data were analyzed; Pickup truck drivers with fatality were 7.4 kg heavier and 4.6 cm taller than passenger car drivers. Most pickup truck drivers were males. Phase 1 extended the study by focusing on the drivers of very large pickup trucks. The size of 1999-2016 Ford F-250 and F-350 drivers involved in fatal crashes was analyzed by age and sex. More than 90% of drivers were males. The average male driver was 179.5 ± 7.5 cm tall and weighed 89.6 ± 18.4 kg.

Phase 2 – Surrogate study: Twenty-nine male surrogates were selected to represent the average size of male drivers of F-250 and F-350s involved in fatal crashes. On average, the volunteers weighed 88.6 ± 5.2 kg and were 180.0 ± 3.2 cm tall with a 95.2 ± 2.2 cm seated height. The volunteers were lap-shoulder belted in the driver seat of a 2002 Ford F-250 crew cab. The head-to-roof clearance was 12.8 ± 1.1 cm. It was 1.0 ± 0.6 cm once the vehicle was statically inverted.

Phase 3 – Drop tests: Three drop tests were conducted using 2002 Ford F-250 crew cab pickups. An instrumented 50th Hybrid III ATD was lap-shoulder belted in the driver seat. The ATD was modified by increasing the seated height by 5 cm, from 88 to 93 cm, to represent the average driver of very large pickups. Biomechanical responses were assessed. All were below Injury Assessment Reference Value (IARV) except for upper and lower neck. The effect of roof/pillar deformation on occupant responses was analyzed by varying the vehicle weight (3147 kg in production test v 1502 kg in the buck test) and roof/pillar strength (production v roll caged). The test data and videos were reviewed to identify time coinciding with ground contact, head-to-roof contact, peak biomechanical responses, and maximum deformation. Upper neck compression was -7,426 N in the production test; it was -8.339 N in the buck test and -7,549 N in the roll caged tests. The loads occurred at about 25 msec in all tests. Maximum roof/pillar deformation occurred 150 ms later in the production test.

Conclusion: Peak neck compressions were similar in the three tests and occurred shortly after initial head contact and prior to significant roof/pillar deformation. Neck injury responses resulted from torso augmentation and were independent of roof system deformation.