ProBiomechanics LLC, Bloomfield Hills, Michigan.
Traffic Inj Prev. 2024;25(3):297-312. doi: 10.1080/15389588.2024.2315890. Epub 2024 Feb 28.
Vehicle and occupant responses in 35 mph NCAP tests were determined for small-midsize passenger cars grouped around model year (MY) 1980, 1990, 2000, 2010 and 2020. A baseline was established with 1980 vehicles not designed for NCAP. The results of four decades of vehicles designed for NCAP were compared to the baseline. The study also determined the risk for serious injury (MAIS 3 + F) by vehicle model year (MY) using 1989-2015 NASS and 2017-2020 CISS. It explored safety trends in frontal crashes over 50 MYs of vehicles.
The 1980 baseline group was established with 10 1979-1983 MY passenger cars weighing <1,500 kg. Four decades of vehicle crash tests from five manufacturers established trends in vehicle dynamics and dummy responses over four decades of vehicles designed for NCAP. Triaxial acceleration of the head and chest were reanalyzed for each test to have a consistent set of responses over five decades. The risk for serious injury (MAIS 3 + F) to the driver and front passenger was determined by vehicle MY using 1989-2015 NASS and 2017-2020 CISS with belted and unbelted drivers and right-front passengers. The data was sorted in four MY groups 1961-1989 MY, 1990-1999 MY, 2000-2009 MY and 2010 MY-2021 MY. The risk for MAIS 3 + F injury was determined with standard errors using weighted data.
The 1980 NCAP tests brought about changes in vehicle structures and occupant restraints by 1990; however, HIC and 3 ms chest acceleration have not changed much the past 20 years since the use of advanced airbags and seatbelts with pretensioner and load-limiters. For the driver, HIC dropped 40 ± 19% from the 1980 to 1990 NCAP tests and dropped further to 76 ± 32% in 2020. The percentage drops after 1990 were not statistically significant. The driver 3 ms chest acceleration dropped 18 ± 5% from 1980 to 1990 and plateaued with 22 ± 6% in 2020. For the front passenger, HIC dropped 68 ± 52% from the 1980 to 1990 NCAP tests and plateaued at 71 ± 49% in 2020. The passenger 3 ms chest acceleration dropped 13 ± 5% from 1980 to 1990 and has fluctuated with minimal change. Injury risks based on responses show the same initial drop in 1990 and have remained essentially constant. Nothing meaningful has changed in dummy responses in the past 20 years of NCAP testing. The field data found the belted driver MAIS 3 + F risk was 1.66 ± 0.37% in 1961-1989 MY vehicles and 1.39 ± 0.33% in 2010-2021 MY vehicles. For belted right-front passengers, the risk was 1.52 ± 0.39% in 1961-1989 MY vehicles and 1.42 ± 0.46% in 2010-2021 MY vehicles. The field data shows no meaningful change in injury risk in 50 MYs of vehicles. NCAP involves 35-40 mph delta-V, which represents a small fraction, 0.33%, of belted occupant exposure and only 8.6% of severe injury based on 1994-2015 NASS.
The NCAP test lacks field relevance. Manufacturers are merely "tuning" the restraint systems for star ratings without meaningful changes in field injury risks the past 20 years. There are disbenefits of "tuning" safety for a single, high-severity crash when most of the severe injury occurs in lower severity crashes. NHTSA should reevaluate plans to change the dummy to Thor and add BrIC injury criteria to assess NCAP responses. These changes would cause manufacturers to further "tune" structures, restraints and interiors without meaningful effects in real-world crashes.
确定围绕 1980 年、1990 年、2000 年、2010 年和 2020 年的车型年分组的小型中型乘用车在 35mph NCAP 测试中的车辆和乘员响应。为没有设计用于 NCAP 的 1980 年车辆建立了基准。将 40 年来设计用于 NCAP 的车辆的结果与基准进行了比较。该研究还使用 1989-2015 年 NASS 和 2017-2020 年 CISS，确定了车辆模型年份（MY）对严重受伤（MAIS 3+F）的风险。它探索了超过 50 年车辆的正面碰撞中的安全趋势。
使用重量小于 1500kg 的 10 辆 1979-1983 年 MY 乘用车建立了 1980 年基线组。来自五家制造商的四个十年的车辆碰撞测试确定了四个十年的车辆设计用于 NCAP 的车辆动力学和假人响应趋势。对头和胸部的三轴加速度进行了重新分析，以便在五个十年中具有一致的响应集。使用 1989-2015 年 NASS 和 2017-2020 年 CISS，通过系安全带和不系安全带的驾驶员和右前乘客，确定驾驶员和前排乘客严重受伤（MAIS 3+F）的风险。数据按四个 MY 组 1961-1989 MY、1990-1999 MY、2000-2009 MY 和 2010 MY-2021 MY 进行分类。使用加权数据确定标准误差的 MAIS 3+F 损伤风险。
1980 年的 NCAP 测试通过 1990 年的车辆结构和乘员约束的变化带来了变化；然而，自使用先进的安全气囊和带有预紧器和限载器的安全带以来，HIC 和 3ms 胸部加速度在过去 20 年中并没有太大变化。对于驾驶员，HIC 从 1980 年至 1990 年的 NCAP 测试中下降了 40%±19%，到 2020 年进一步下降至 76%±32%。1990 年以后的百分比下降没有统计学意义。驾驶员 3ms 胸部加速度从 1980 年至 1990 年的 NCAP 测试中下降了 18%±5%，到 2020 年稳定在 22%±6%。对于前排乘客，HIC 从 1980 年至 1990 年的 NCAP 测试中下降了 68%±52%，到 2020 年稳定在 71%±49%。乘客 3ms 胸部加速度从 1980 年至 1990 年的 NCAP 测试中下降了 13%±5%，并在最小变化范围内波动。基于响应的伤害风险显示出相同的初始下降，并且基本上保持不变。在过去 20 年的 NCAP 测试中，假人响应没有发生任何有意义的变化。现场数据发现，在 1961-1989 年的 MY 车辆中，系安全带的驾驶员 MAIS 3+F 风险为 1.66%±0.37%，在 2010-2021 年的 MY 车辆中为 1.39%±0.33%。对于系安全带的右前乘客，在 1961-1989 年的 MY 车辆中，风险为 1.52%±0.39%，在 2010-2021 年的 MY 车辆中为 1.42%±0.46%。现场数据显示，50 年的车辆中没有发生有意义的伤害风险变化。NCAP 涉及 35-40mph 的 delta-V，代表安全带乘员暴露的一小部分，0.33%，仅占基于 1994-2015 年 NASS 的严重伤害的 8.6%。
NCAP 测试缺乏现场相关性。制造商只是在没有对过去 20 年现场伤害风险产生有意义变化的情况下，对约束系统进行“调整”以获得星级评级。当大多数严重伤害发生在较低严重程度的碰撞中时，对单次高严重程度碰撞进行“调整”安全会带来不利影响。NHTSA 应重新评估改变假人至 Thor 并增加 BrIC 伤害标准以评估 NCAP 响应的计划。这些变化将导致制造商进一步“调整”结构、约束和内饰，而在现实世界的碰撞中不会产生有意义的影响。
