GRE写作范文学习：道路设施改善

　　In an attempt to improve highway safety, Prunty County last year lowered its speed limit from 55 to 45 miles per hour on all county highways. But this effort has failed: the number of accidents has not decreased, and, based on reports by the highway patrol, many drivers are exceeding the speed limit. Prunty County should instead undertake the same kind of road improvement project that Butler County completed five years ago: increasing lane widths, resurfacing rough highways, and improving visibility at dangerous intersections. Today, major Butler County roads still have a 55 mph speed limit, yet there were 25 percent fewer reported accidents in Butler County this past year than there were five years ago.

　　Write a response in which you discuss what specific evidence is needed to evaluate the argument and explain how the evidence would weaken or strengthen the argument.

　　【满分范文赏析】

　　This author argues that a recent reduction in Prunty County's speed limit on its major roads (55 to 45 miles per hour miles per hour) has proven ineffective and that the county should rescind the speed limit change. Instead, urges the author, the city should focus on infrastructure improvement, much like Butler County, wherein drivers experienced a 25% reduction in accidents while enjoying speeds of up to 55 miles per hour. After a review of the assumptions therein, the integrity of the argument comes into question.

　　【本段结构】

　　本文采用了标准的Argument开头段结构，即C—A—F的开头结构。本段首先概括原文的Conclusion，之后简要提及原文为支持其结论所引用的一系列Assumption及细节，最后给出开头段到正文段的过渡句，指出原文的Flaw，即这些Assumption无法让原文逻辑上没有问题。

　　【本段功能】

　　作为Argument开头段，本段具体功能就在于发起攻击并概括原文的结论，即Prunty地区应当采取和Butler地区相同的道路设施改善计划。本段接下来提到了原文中为支持之前的Conclusion所提供的证据，即在Prunty地区采取的限速政策没效果，以及在Butler地区采取的道路设施改善计划减少了事故。文章提及这些信息，为是在正文段中对这些Assumption即将进行的具体攻击做铺垫。

　　Firstly, only recently has the speed limit in Pruntly County been reduced and only for major roads. Perhaps not enough time has passed to determine the change’s effectiveness. Further, no indication of results from a study on the roadways with a speed limit change has been provided. Lacking such a link between the conclusions that Prunty's road safety effort initiative has failed is invalidated.

　　【本段结构】

　　本段采用了标准的Argument正文段结构，即先是提及原文的第一个逻辑错误，之后分析该逻辑错误的原因，接下来，进一步分析这样的错误为什么让原文的Conclusion不成立。

　　【本段功能】

　　作为正文第一段，本段攻击原文所犯的第一个重要逻辑错误——样本类错误。原文提到在采取限制速度一年后，Pruntly地区的事故发生率没有下降。但是，这些样本并不一定有说服力，毕竟，短短的一年时间并不能让人们看到这个限速政策的实际效果。所以，原文当中的这个观点是站不住脚的。

　　Secondly, the argument assumes that all other factors affecting highway accident rates have remained unchanged since the county lowered its speed limit. However, the author fails to provide evidence to support this assumption. It is entirely possible that the lower speed limit does in fact serve to reduce the accident rate, while some other factor, such as unseasonably poor weather, reduced law enforcement measures, or even an influx of teenage drivers to the area, has served to increase the accident rate. Without considering and ruling out these and other factors that might have served to increase the accident rate since the speed limit was lowered, the author cannot justifiably conclude that this safety effort has failed.

　　【本段结构】

　　本段采用了标准的Argument正文段结构，即先是提及原文的第二个逻辑错误，之后分析该逻辑错误的原因，接下来，进一步分析这样的错误为什么让原文的Conclusion不成立。

　　【本段功能】

　　作为正文第二段，本段攻击原文所犯的第二个重要逻辑错误——因果类错误。原文提到在采取限制速度后，Pruntly地区的事故发生率没有下降。但是，原文忽视了可能造成事故的其它因素。而相比之下，限速政策实际上有助于避免交通事故的发生。在没有考虑到这些相关因素的情况下，原文并不能证明这个观点是合理的。

　　Thirdly, in the argument, the author implies that the higher speed limit in Butler County has not served to increase the incidence of road accidents in that county. It is entirely possible that the 55-mph speed limit actually serves to increase the accident rate on Butler's highways, but that others factors, such as stricter law enforcement measures or improved driver education, have served to decrease the accident rate to a greater extent. Without considering and ruling out these and other factors which might have served to decrease the accident rate in Butler County, the author cannot confidently recommend that Prunty County emulate Butler County’s approach to the problem.

　　【本段结构】

　　本段采用了标准的Argument正文段结构，即先是提及原文的第三个逻辑错误，之后分析该逻辑错误的原因，接下来，进一步分析这样的错误为什么让原文的Conclusion不成立。

　　【本段功能】

　　作为正文第三段，本段攻击原文所犯的第三个重要逻辑错误——因果类错误。原文提到在Butler地区没有采取限速政策并不会给当地的交通事故带来负面的影响。但事实上，这样的因果关系可能被颠倒了。相比之下，如果采取了限速，Butler地区可能会更安全。在没有考虑到这些相关因素的情况下，原文当中的这个观点是不合逻辑的。

　　In conclusion, to strengthen the argument, the author must better assess the impact of the new speed limit on road safety, with more statistical information about the accident rate on Prunty's major roads, collected over a longer time period. Additionally, the author must account for all other factors that might influence the accident rate on roads in both counties

　　【本段结构】

　　本段采用的Argument结尾段结构是单纯的Suggestion结构。即本段给出了可以增强原文说服力的合理建议Suggestion，包括原文作者需要进一步提供的证据和信息等。

　　【本段功能】

　　本段作为Argument结尾段，具体功能为对原文当中的逻辑问题提出建议。段落给出合理的建议包括：作者必须通过更多的统计信息，更好地评估限速政策和道路安全的关系，而且这些信息是在长期观察下得来的结果;此外，作者必须考虑到能对交通事故产生影响的其它相关因素。不难发现，结尾段总结提出的建议与正文各段中依次攻击的错误遥相呼应，即分别对应了样本类错误和因果类错误，这使全篇文章显得浑然一体。