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 55mph 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.
It is concluded that Prunty County should undertake the same kind of road improvement project that Butler County completed five years ago to replace its reduction in the speed limit. 套话： The missing of the crucial pieces of evidence renders the logic of the argument vulnerable.。
The first piece of evidence the author omits to provide is the total traffic volumes before the speed limit and after. A large number of accidents out of a large traffic volume may represent a small chance of accidents. Likewise, a small number of accidents may represent great incidence of accidents if the traffic volume is small. It is the proportion of the accidents to the total traffic volume that decides the likelihood – the rate – of accidents, and the reduced rate is the key to the improved level of highway safety, whereas the decrease in the number of accidents is not without knowing the total number of cars on the highway.
Another missing piece of evidence is the similarity between the causes of accidents in Prunty County and those in Butler County. The effectiveness of a road improvement project may vary from county to county. In other words, the project may be effective in Butler County and ineffective in Prunty County. If the causes of accidents in the two counties are different, Butler County's experience may not be as transferable as thought.
The reduction in the number of accidents in Butler County may not be attributed to the road improvement project but to a number of other factors, such as the decreased traffic volume, drivers’ improved driving behavior and safety awareness. However, the argument provides no evidence to rule out these possibilities, the causative relation between the project and the decreased number of accidents is rendered vulnerable.
None of the annual numbers of accidents two years ago, three years ago and four years ago are known. The lack of the crucial evidence renders it unclear that the project has been effective or that last year was an instance that the accidents decreased for other reasons as is mentioned before. Without having the evidence, it is fair to believe that the annual number of accidents in the past few years immediately after Butler County’s road improvement project increased, and as a result, the project may not be as effective as thought.
The author confuses reported accidents with accidents that actually took place. A piece of evidence that is missing at this point is whether every accident that occurs is reported. It is not unlikely that some of the accidents were not reported when they happened, and as a result, it is likely that the total number of accidents did not decrease.
Unless the author provides the aforementioned evidence, which is however omitted in the line of reasoning, Prunty County should not negate its reduction in the speed limit or to undertake the same kind of road improvement project that Butler County completed five years ago.