The following appeared in a letter to the editor of a local newspaper.
“Commuters complain that increased rush-hour traffic on Blue Highway between the suburbs and the city center has doubled their commuting time. The motorists’ lobby’s favored proposal is to widen the highway, adding lane of traffic. But last year’s addition of a lane to the nearby Green Highway was followed by a worsening of traffic jams on it. A better alternative is to add a bicycle lane to Blue Highway. In addition, many area residents are keen bicyclists. A bicycle lane would encourage them to use bicycles to commute, and so would reduce rush-hour traffic rather than fostering an increase.”
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.
The argument cites the example of the Green Highway to illustrate that widening Blue Highway would not increase traffic congestion. However, it does not note any evidence in support of this claim. Furthermore, the statement fails to consider that the addition of bicycle lanes to Blue Highway might also cause an increase in traffic. Thus, it leaves the reader with the impression that congestion on Blue Highway, if unlikely, is unlikely. Therefore, while the writer presents some evidence to support the claim that bicyclists might prefer Blue Highway over Green Highway, it fails to provide sufficient evidence to suggest that traffic on Blue Highway would not increase due to the addition of a bicycle lane.
The sentence that begins the letter cites a motorist’s group favoring the proposal of widening Blue Highway. The motorist’s group may favor the proposal because its members favor policies that increase vehicle traffic. If motorist groups believe that more vehicles on the road will somehow lead to less congestion, widening Blue Highway would be consistent with their philosophy. The sentence also cites the motorist’s lobby as supporting the proposal. However, there is no indication of who the motorist’s lobby is comprised of or what its agenda is. What motivates these lobby groups? Is it a concern for traffic congestion for commuters? If so, then the group may be biased in favor of the proposal because its members would be directly affected. However, if the group’s goal is to promote increased transportation options, widening Blue Highway would not be consistent with its agenda. Furthermore, a motorist’s lobby that lobbies for wider roads could be supported by special interest groups, such as automobile manufacturers, that would benefit from increased vehicular traffic. The motorist’s lobby and its agenda are a crucial component of the claim, and the writer should have provided more information about them.
The letter also cites evidence that bicyclists would prefer to use Blue Highway instead of Green Highway. The writer provides a brief anecdote about a bicycle commuter who told a reporter that bicyclists preferred Blue Highway because it had fewer cars. This statement is unsupported by the writer’s assertion. The writer could cite statistics that show an increase in bicycling on Blue Highway. However, he does not do so. Instead, he relies on the anecdote of one individual. The writer does not follow that anecdote with further evidence, such as how many bicyclists ride the road or where they ride. Without this information, the reader is left without any firm evidence to accept or reject the statement.
The only concrete evidence presented in the letter is the claim that the addition of bicycle lanes to the Blue Highway resulted in a worsening of traffic on Green Highway. However, this claim is faulty. The writer provides no context for the statement. What evidence does the writer have to back up the claim that traffic on Green Highway worsened after the addition of a bicycle lane? Or did traffic on Green Highway stagnate after the addition of the lane? Without this information, the reader is left to speculate why traffic on Green Highway worsened. Perhaps congestion on Green Highway was already bad. In that case, adding a bike lane would not have increased traffic. Or, maybe the car was moving at the same speed as before, but traffic was heavier, and the addition of a bicycle lane resulted in congestion. Without this information, it is impossible to judge whether adding a bicycle lane caused traffic on Green Highway to worsen.
The writer’s final claim that bicyclists might reduce their commute times by riding a bicycle instead of driving is not backed up with evidence. The writer does provide anecdotal evidence to support a claim that bicyclists might prefer Blue Highway over Green Highway. However, this evidence is insufficient to prove the assertion that bicyclists would decrease traffic on Blue Highway by riding a bicycle instead of driving. The writer could have presented statistics showing that more people ride bikes on Blue Highway than Green Highway. But he does not. Instead, he writes that “many area residents are keen bicyclists.” This vague statement does not prove anything. Without data, the reader is left to assume that bicyclists prefer Blue Highway to Green Highway.
The letter contains a great deal of unsubstantiated information. The writer could have used statistics to back up his claims. The claim that traffic congestion on Blue Highway would increase due to adding a bicycle lane is not credible without substantial evidence. The writer could have undermined his claim by presenting evidence that bicyclists prefer to avoid Blue Highway and that widening the road would cause more congestion than it decreases. The writer’s assertion that bicyclists might reduce their commute times by riding a bicycle instead of driving is unsupported. Without statistics, it is impossible to know whether the number of bicyclists on Blue Highway would rise if a bicycle lane were added.
The writer failed to present any substantial evidence to support his claim that traffic congestion on Blue Highway would increase due to adding a bicycle lane. His assertion that bicyclists might reduce their commute times by riding a bicycle instead of driving is also unfounded. Without statistics, it is impossible to know whether the number of bicyclists on Blue Highway would rise if a bicycle lane were added.