In the nation of Partoria, large trucks currently account for 6 percent of miles driven on Partoria's roads but are...
GMAT Critical Reasoning : (CR) Questions
In the nation of Partoria, large trucks currently account for 6 percent of miles driven on Partoria's roads but are involved in 12 percent of all highway fatalities. The very largest trucks—those with three trailers—had less than a third of the accident rate of single- and double-trailer trucks. Clearly, therefore, one way for Partoria to reduce highway deaths would be to require shippers to increase their use of triple-trailer trucks.
Which of the following, if true, most seriously weakens the argument?
Passage Analysis:
| Text from Passage | Analysis |
|---|---|
| In the nation of Partoria, large trucks currently account for 6 percent of miles driven on Partoria's roads but are involved in 12 percent of all highway fatalities. |
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| The very largest trucks—those with three trailers—had less than a third of the accident rate of single- and double-trailer trucks. |
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| Clearly, therefore, one way for Partoria to reduce highway deaths would be to require shippers to increase their use of triple-trailer trucks. |
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Argument Flow:
The argument starts with a general safety problem (large trucks are disproportionately dangerous), then introduces specific data showing that the largest trucks are actually much safer than smaller trucks, and concludes that increasing use of these safer large trucks will reduce deaths.
Main Conclusion:
Partoria should require shippers to increase their use of triple-trailer trucks to reduce highway deaths.
Logical Structure:
The argument uses a comparison within truck types to support its recommendation. The logic is: since triple-trailer trucks have much lower accident rates than other trucks, using more of them instead of single/double-trailer trucks will reduce overall highway fatalities.
Prethinking:
Question type:
Weaken - we need to find information that would reduce our belief in the conclusion that requiring more triple-trailer trucks would reduce highway deaths
Precision of Claims
The argument makes specific quantitative claims: trucks are 6% of miles but 12% of fatalities, and triple-trailers have less than 1/3 the accident rate of single/double-trailers. The conclusion recommends requiring shippers to increase use of triple-trailer trucks to reduce deaths.
Strategy
To weaken this argument, we need to find reasons why increasing triple-trailer truck usage might NOT reduce highway deaths, even though they have lower accident rates. We should look for hidden costs, implementation problems, or reasons why the safety comparison might be misleading or irrelevant to the overall goal.
This tells us that smaller roads will remain off-limits to large trucks regardless of regulatory changes. However, this doesn't weaken the argument about using more triple-trailer trucks on highways where large trucks are already permitted. The argument focuses on highway fatalities, and this choice doesn't challenge whether triple-trailer trucks would be safer than other large trucks on those highways.
This is our answer! This choice reveals that only the best, most experienced drivers have been operating triple-trailer trucks so far. This seriously weakens the argument because it suggests the lower accident rate might be due to superior driver skill rather than the trucks being inherently safer. If we require increased use of triple-trailer trucks, average drivers would start operating them, and we might lose the safety advantage entirely. The argument assumes the trucks themselves are safer, but this shows the safety difference could be explained by driver quality instead.
This tells us that most fatal truck collisions don't involve two trucks colliding with each other. This doesn't weaken the argument because the recommendation is about replacing single/double-trailer trucks with triple-trailer trucks, not about reducing truck-to-truck collisions specifically. The safety comparison still holds regardless of what types of vehicles trucks typically collide with.
This mentions that the trucking industry's overall safety record has improved slightly over ten years. This doesn't weaken the argument about using more triple-trailer trucks. If anything, it might suggest that safety improvements are possible, but it doesn't challenge whether triple-trailer trucks are safer than other large trucks or whether using more of them would reduce deaths.
This tells us about payload capacity differences between truck types. However, the argument is based on accident rates per truck, not per unit of cargo carried. Even if triple-trailer trucks carry less than three times the payload of single-trailer trucks, they could still reduce overall highway deaths by having lower accident rates, which is what the argument claims.