generis wrote:
Urban rail systems have been proposed to alleviate traffic congestion, but results in many cities have been cited as evidence that this approach to traffic management is ineffective. For example, a U.S. city that opened three urban rail branches experienced a net decline of 3,100 urban rail commuters during a period when employment increased by 96,000. Officials who favor urban rail systems as a solution to traffic congestion have attempted to counter this argument by noting that commuting trips in that city represent just 20 percent of urban travel.
The response of the officials to the claim that urban rail systems are ineffective is most vulnerable to criticism on the grounds that it
A) presents no evidence to show that the statistics are incorrect
B) relies solely on general data about U.S. cities rather than data about the city in question
C) fails to consider that commuting trips may cause significantly more than 20 percent of the traffic congestion
D) fails to show that the decline in the number of urban rail commuters in one U.S. city is typical of U.S. cities generally
E) provides no statistics on the use of urban rail systems by passengers other than commuters
CR11080.02
Problem: Traffic congestion (too may cars on the roads)
Debate between supporters and opposers of Urban Rail:
Supporters of Urban Rail: Urban Rail reduces congestion.
Opposers of Urban Rain: Not effective. In a city, when employment increased by 96,000, there was a decline of 3100 commuters (people who travel to and fro office every day). So urban rail did not reduce congestion.
Supporters of Urban Rail: Commuter trips represent just 20% of travel in that city. (The commuter trips are not the main source of congestion. Perhaps other 80% cause congestion and they have been using the urban rail and hence reducing congestion. So reduction in commuter trips doesn't say much about whether rails are effective. So if one small fraction isn't using the urban rails much, it doesn't matter. Perhaps others are using and hence traffic is lower)
What will criticise this response of supporters?
A) presents no evidence to show that the statistics are incorrect
The statistics needn't be incorrect.
B) relies solely on general data about U.S. cities rather than data about the city in question
It does talk about that city.
C) fails to consider that commuting trips may cause significantly more than 20 percent of the traffic congestion
Correct. The supporters are supporting - "Urban rail reduces congestion."
Now, what if most of the congestion is caused by commuters even though commuter travel is just 20% of travel? What if the morning and evening office times are the times of congestion because the roads cannot handle so much commuter traffic. The other travel could be staggered around the day causing no congestion. Then if commuters are not using urban rail, it doesn't help in reducing congestion.
Commuters may not be a big part of the total travellers but they could be the whole and sole cause of the congestion problem.
D) fails to show that the decline in the number of urban rail commuters in one U.S. city is typical of U.S. cities generally
Not correct. The opposers cited the example of one city and the supporters are presenting evidence in the case of that city itself.
E) provides no statistics on the use of urban rail systems by passengers other than commuters
Not correct. They are providing an explanation for why the commuters data given by opposers is not relevant. The opposers talked about commuters.
Answer (C)
In option E, the remaining 80% of the travel can cause congestion, which the proponent has not talked about. Hence, even if commuters form only 20%, the remaining 80% can cause congestion, and hence bringing them to rail would release congestion. Or he tries to justify the usefulness by commenting only on 20% of the total travel, which is wrong. Why isn't option E correct then?