无人驾驶汽车更安全？该问题或许无解

无人驾驶汽车的优点之一，就是据说它比有人驾驶汽车要更安全。根据全美公路交通安全管理局的统计，在所有车祸中，有高达94%的比例是由人为失误导致的，这些人为失误包括酒驾、超速、分心和疲劳驾驶等。

不过近日的一份研究报告显示，无人驾驶汽车不论进行多少小时的测试，都不足以确定其安全性。

该报告来自美国著名智库兰德公司。报告称，无人驾驶汽车恐怕需要经过“几亿甚至几千亿英里的路试”，才能获得足够的信息来比较出它与有人驾驶汽车二者哪个安全系数更高。这样彻底的测试可能需要“几十年甚至几百年的时间”。要想在交付消费者正常使用前完成如此巨量的测试任务，显然是不切实际的。

根据来自美国交通部的数据显示，2013年，美国有229万人在车祸中受伤，32,028人因车祸死亡。这些数字虽然触目惊心，却是建立在美国人民每年要合计驾车行驶3万亿英里的基础上的。

这份研究报告的联合撰稿人、兰德公司的高级统计学家苏珊•帕多克在公司的一份声明中表示：“在研发无人驾驶技术的公司中，最长记录在案的路试里程是130万英里，光是如此也耗费了好几年的时间。即便无人驾驶汽车进行了1000万英里的路试，我们也无法对它的安全性和可靠性给出统计学意义上的结论。”

兰德公司的研究人员还指出，无人驾驶行业有必要开发其它的测试方法，以检验无人驾驶汽车是否真的比有人驾驶汽车安全。

据谷歌公司披露，该公司的无人驾驶汽车项目启动以来，其测试车辆已经出过大大小小十余次事故。不过谷歌还表示，所有事故都是由人为因素导致的。（但是截止到目前，谷歌测试车上的真人驾驶员也成功避免了13次事故的发生。）话虽如此，但从密歇根大学交通研究所的研究人员布兰登•舒特勒和迈克尔•席瓦克提供的数据来看，无人驾驶汽车发生事故的机率高达有人驾驶汽车的五倍。他们还发现，同样在发生交通事故时，无人驾驶汽车的成员受伤的人数要高于传统汽车，但目前尚无无人驾驶汽车导致乘员死亡的报告。

舒特勒和席瓦克的这份分析报告发布于2015年10月，所用的数据部分来自加州有关部门的公开数据，但更多的数据还是来自谷歌。他们将有关事故数据与2013年的全美道路交通安全记录进行了对比。研究人员指出，各大无人驾驶技术公司所记录的路试里程与传统的有人驾驶汽车相比，还是很低的。

从现有事故报告来看，在任何一起事故中，无人驾驶汽车都不是主要过错方。它们往往是在停车或者在车流中缓慢移动时被其他车辆撞击，最频繁的事故就是被追尾。

另外，随着技术的持续突飞猛进，将来与无人驾驶汽车有关的事故数量也可能会进一步下降。（财富中文网）

译者：朴成奎

One of the arguments for self-driving cars is thatthey will be safer than human-driven vehicles.Human error is the cause of 94% of car crashes, according to the National Highway Traffic Safety Administration. Those errors include drunk driving, speeding, distraction, and fatigue.

But a new report finds that self-driving cars can’t be tested enough hours to determine their safety.

Thereport from research firm RAND Corporation says autonomous vehicles would need to be tested “hundreds of millions of miles and sometimes hundreds of billions of miles” to gain enough information to compare its safety to human-driven automobiles. Such thorough testing would require “tens and sometimes hundreds of years,” which would make it impractical to accomplish before clearing the vehicles for regular consumer use, the report said.

According to the U.S. Department of Transportation, there were 2.29 million auto-related injuries and 32,028 fatalities on the highways in 2013. However, those numbers come in the context of the 3 trillion total miles driven annually in the U.S.

“The most autonomous miles any developer has logged are about 1.3 million, and that took several years,” study co-author and RAND senior statistician Susan Paddock said in a company statement. “Even if autonomous vehicle fleets are driven 10 million miles, one still would not be able to draw statistical conclusions about safety and reliability.”

The RAND researchers say that industry needs to develop other ways to examine whether self-driving vehicles are safer than those piloted by humans.

Google has said there have been more than a dozen accidents with its self-driving cars since the self-driving car project began. But it has said all of those were caused by humans. (However, human drivers have prevented the autonomous vehicles fromcausing an accident 13 times so far.)

Still, data from researchers Brandon Schoettle and Michael Sivak from the University of Michigan Transportation Research Institute found that self-driving vehicles have been nearly five times as likely to get into accidents as those driven by humans. They also saw somewhat elevated numbers of injuries per crash compared to normal traffic but no fatalities.

Schoettle and Sivak based their October 2015 analysis on available data from California as well as more extensive data from Google. They then compared the number of accidents to 2013 national safety records. The researchers noted that the amount of recorded miles was low compared to conventional traffic.

The automated cars weren’t at fault in any of the crashes. Instead, they were struck when stopped or moving slowly in traffic and most frequently were rear-ended.

Also, as the technology continues to advance rapidly, improvements might help reduce the number of accidents involving self-driving cars going forward.