The following appeared in the editorial section of a newspaper in the country of West Cambria: “The practice of officially changing speed limits on the highways—whether by increasing or decreasing them—is a dangerous one. Consider what happened over the past decade whenever neighboring East Cambria changed its speed limits: an average of 3 percent more automobile accidents occurred during the week following the change than had occurred during the week preceding it—even when the speed limit was lowered. This statistic shows that the change in speed limit adversely affected the alertness of drivers.”

The following appeared in the editorial section of a newspaper in the country of West Cambria:

“The practice of officially changing speed limits on the highways—whether by increasing or decreasing them—is a dangerous one. Consider what happened over the past decade whenever neighboring East Cambria changed its speed limits: an average of 3 percent more automobile accidents occurred during the week following the change than had occurred during the week preceding it—even when the speed limit was lowered. This statistic shows that the change in speed limit adversely affected the alertness of drivers.”

Discuss how well reasoned you find this argument. In your discussion be sure to analyze the line of reasoning and the use of evidence in the argument. For example, you may need to consider what questionable assumptions underlie the thinking and what alternative explanations or counterexamples might weaken the conclusion. You can also discuss what sort of evidence would strengthen or refute the argument, what changes in the argument would make it more logically sound, and what, if anything, would help you better evaluate its conclusion.

(A)The authors of this argument contend that changing the speed limit on highways is a bad idea, because doing so would increase the likelihood of accidents. Their argument that changing the speed limit would increase the number of accidents is based on the assumption that more accidents occurred during the week following the change than during the week preceding it. However, it is not always the case that an accident rate increases after a speed limit increase. That is not necessarily the case because other factors besides the speed limit change come into play, such as increased traffic volume or the failing of drivers to adjust to the new speed. Additionally, even if the speed limit change did increase the number of accidents, the increase would not be significant when compared to the overall rate of accidents on the highway. To bolster their claim, the authors cite data showing that the number of accidents increased by 3 percent in the week following each speed limit change. However, the 3 percent increase is not statistically significant. Therefore, the data cannot be used to show that changing the speed limit is dangerous

The authors assert that accidents are increased after the speed limit is lowered. However, they were careful to note that the accidents increased when the speed limit was lowered, which excludes the possibility that the accidents are increased when the speed limit is raised. Therefore, the authors may have inadvertently presented a false dichotomy. Their premise is flawed because the evidence would indicate that the accident rates do not differ between lowering and raising the speed limit. If the conditions on the highway were the same before and after the changes, then the change in the speed limit could have no effect on accidents. It is only when additional factors come into play that change the speed limit could have an affect on accidents. For example, a speed camera or radar trap may have been installed after the change, which would detect vehicles driving over the posted speed limit. In that case, the accident rate would logically increase. Alternatively, if the speed limit change coincided with a large increase in traffic volume on the highway, then the accident rate would logically increase as well. The effect would be similar to the speed camera example

Another factor that would affect the number of accidents is the inability of drivers to adjust to the new speed limit. If a driver has become accustomed to traveling at 70 mph on a highway, then he or she might find it difficult to adjust to driving 55 mph, even if the speed limit has not changed. Therefore, the new speed limit might not alter the accident rate, because drivers are simply unable to adjust to the new speed. In a similar vein, a driver who is easily startled by hazards on the highway might slow down to 50 mph to avoid an accident, even if the posted speed limit is 55 mph. In that case, the accident rate would logically decrease

The authors also suggest that accident rates increase when the speed limit is lowered. This statement assumes that the number of accidents is a reliable indicator of driving skills, which is questionable. For example, if a driver is traveling at 55 mph on a highway, and then an accident occurs, that driver might be distracted or negligent, regardless of the speed limit. Therefore, the accident rate might increase even if the posted speed limit is 55 mph. To conclude, changing the speed limit of a highway does not result in an increased rate of accidents, although other factors, such as a change in traffic flow, do affect the number of accidents. Therefore, changing the speed limit is not a dangerous practice.