Automobile Research Institute (INSIA), Campus Sur de la UPM, Carretera de Valencia km. 7, 28031 Madrid, Spain.
Accid Anal Prev. 2010 Nov;42(6):1621-31. doi: 10.1016/j.aap.2010.03.020. Epub 2010 May 7.
This paper investigates the relationship between a passenger car's year of registration and its crashworthiness and aggressivity in real-world crashes. Crashworthiness is defined as the ability of a car to protect its own occupants, and has been evaluated in single and two-car crashes. Aggressivity is defined as the ability to protect users travelling in other vehicles, and has been evaluated only in two-car crashes. The dependent variable is defined as the proportion of injured drivers who are killed or seriously injured; following previous research, we refer to this magnitude as injury severity. A decrease in the injury severity of a driver is interpreted as an improvement in the crashworthiness of their car; similarly, a decrease in the injury severity of the opponent driver is regarded as an improvement in aggressivity. Data have been extracted from the Spanish Road Accident Database, which contains information on every accident registered by the police in which at least one person was injured. Two types of regression models have been used: logistic regression models in single-car crashes, and generalised estimating equations (GEE) models in two-car crashes. GEE allow to take account of the correlation between the injury severities of drivers involved in the same crash. The independent variables considered have been: year of registration of the subject car (crashworthiness component), year of registration of the opponent car (aggressivity component), and several factors related to road, driver and environment. Our models confirm that crashworthiness has largely improved in two-car crashes: when crashing into the average opponent car, drivers of cars registered before 1985 have a significantly higher probability of being killed or seriously injured than drivers of cars registered in 2000-2005 (odds ratio: 1.80; 95% confidence interval: 1.61; 2.01). In single-car crashes, the improvement in crashworthiness is very slight (odds ratio: 1.04; 95% confidence interval: 0.93; 1.16). On the other hand, we have also found a significant worsening in aggressivity in two-car crashes: the driver of the average car has a significantly lower probability of being killed or seriously injured when crashing into a car registered before 1985, than when crashing into a car registered in 2000-2005 (odds ratio: 0.52; 95% confidence interval: 0.45; 0.60). Our results are consistent with a large amount of previous research that has reported significant improvements in the protection of car occupants. They also add to some recent studies that have found a worsening in the aggressivity of modern cars. This trend may be reflecting the impact of differences in masses and travel speeds, as well as the influence of consumer choices. The precise reasons have to be investigated. Also, the causes have to be found for so large a discrepancy between crashworthiness in single and two-car crashes.
本文研究了乘用车注册年份与其在实际事故中的耐撞性和攻击性之间的关系。耐撞性定义为汽车保护自身乘客的能力，已在单车和两车碰撞中进行了评估。攻击性定义为保护在其他车辆中行驶的用户的能力，仅在两车碰撞中进行了评估。因变量定义为受伤驾驶员中死亡或重伤的比例；根据以往的研究，我们将这一程度称为伤害严重程度。驾驶员伤害严重程度的降低被解释为其汽车耐撞性的提高；类似地，对手驾驶员伤害严重程度的降低被视为攻击性的提高。数据取自西班牙道路事故数据库，该数据库包含了由警方登记的每起造成至少一人受伤的事故信息。使用了两种回归模型：单车碰撞中的逻辑回归模型和两车碰撞中的广义估计方程（GEE）模型。GEE 允许考虑同一事故中涉及的驾驶员伤害严重程度之间的相关性。考虑的自变量有：受试汽车的注册年份（耐撞性成分）、对手汽车的注册年份（攻击性成分）以及与道路、驾驶员和环境相关的几个因素。我们的模型证实，两车碰撞中的耐撞性有了很大提高：当与平均对手车相撞时，1985 年前注册的汽车的驾驶员比 2000-2005 年注册的汽车的驾驶员更有可能死亡或重伤（优势比：1.80；95%置信区间：1.61；2.01）。在单车碰撞中，耐撞性的提高非常轻微（优势比：1.04；95%置信区间：0.93；1.16）。另一方面，我们还发现两车碰撞中的攻击性明显恶化：当与 1985 年前注册的汽车相撞时，平均汽车的驾驶员比与 2000-2005 年注册的汽车相撞时更不可能死亡或重伤（优势比：0.52；95%置信区间：0.45；0.60）。我们的结果与大量先前的研究一致，这些研究报告了对汽车乘客保护的重大改进。它们还补充了一些最近的研究，这些研究发现现代汽车的攻击性恶化。这种趋势可能反映了质量和行驶速度差异的影响，以及消费者选择的影响。必须调查确切的原因。此外，还必须找到单车和两车碰撞中耐撞性差异如此之大的原因。
