One way to compare the relative safety of vehicles is to look at driver death rates. From time to time, IIHS researchers compute the rate at which drivers of individual models are killed in crashes. Rates are given as the number of driver deaths per million registered vehicle years. (A registered vehicle year is one vehicle registered for one year.) To increase the exposure and thereby improve the accuracy of the calculations, results are included for the previous three model years if the vehicle wasn't substantially redesigned during that time. These calculations take into account only deaths of drivers, not passengers, since every vehicle that crashes has a driver, but not every vehicle has passengers.
These calculations take into account only deaths of drivers, not passengers, since every vehicle that crashes has a driver, but not every vehicle has passengers.
要论汽车安全性，是要以人身安全为终极目的，不是吗？下面这个帖子说的非常好：
IIHS 有详细的实际车祸死亡率统计数字，我把最新的2011-2014年统计都看了一遍，结论是与安全性最相关的应该是司机是否采取安全驾驶的方式，同样是大型车也有车祸死亡率非常高的（高于大多数小型车），比如 Dodge Challenger 大型车。
从数据看，除了要避免微型车（mini-size cars）外，实际死亡率跟车的大中小关联性也不强。
实际数据最不支持的就是所谓日车安全性较差的偏见。正相反，TOYOTA/LEXUS的安全性名列前茅，在0死亡率的车型里日车也占比较大比例。美系、韩系车排名靠后。
实际死亡率统计表格如下：
超小型车要避免：
与安全性最相关的是司机的驾驶方式，大型车也有车祸死亡率非常高的，比如：
“
Driver death rates by make and modelOne way to compare the relative safety of vehicles is to look at driver death rates. From time to time, IIHS researchers compute the rate at which drivers of individual models are killed in crashes. Rates are given as the number of driver deaths per million registered vehicle years. (A registered vehicle year is one vehicle registered for one year.) To increase the exposure and thereby improve the accuracy of the calculations, results are included for the previous three model years if the vehicle wasn't substantially redesigned during that time. These calculations take into account only deaths of drivers, not passengers, since every vehicle that crashes has a driver, but not every vehicle has passengers.
并没说只统计单车死亡
These calculations take into account only deaths of drivers, not passengers, since every vehicle that crashes has a driver, but not every vehicle has passengers.
查找数据是好事，但更重要的是独立思考，是不是？There are lies, damned lies and statistics. 无论哪个数据都要思考里面可能有意无意骗人的地方。
NHTSA是政府机构吧？
但是每个消费者要达到个人最佳，都不会是和群体优化的选择相同的。在安全性上我没有固有观点，但我很清楚群体优化的数据对个人选择很有害。
也讲清楚为什么NHTSA数据不能用来个人选择。欢迎你讨论，扔个政府机构出来是压不住独立思考的。然后你也不要混淆概念，我没有质疑NHTSA数据，质疑的是你对数据应用范围的理解。
是受很多个人因素影响的
那不就成了自说自话了？
避免微型车，别盲目相信美系大型车，安全驾驶最重要
消费者理性选择方法：1，在价位范围内选最重的那些，10%范围内。2，看被动碰撞测试分数，选综合最高的；忽略主动撞墙、单车翻滚分数。3，选完车之后，按车的刹车、操控性能决定怎样是安全驾驶。
如果对数据不认同，就引用更科学，更合理的数据，把个人观点排除，否则是鸡鸭说不到一块。
回到你最初的问题，为什么总是大车和小车比，你或许是作为一个rhetorical question来问的，但其实是很简单的数学原理而已。回了那么多，希望你少搬运，多思考而已。如果觉得我condescending了，那么抱歉。
尊重但不认同你的观点。