Studies have shown that pedestrians are struck by cars when crossing streets in crosswalks more often than they are s...

Irina on August 31, 2019

@dace,

The argument cites evidence that pedestrians are struck by cars when crossing in crosswalks more often than when crossing elsewhere. The author then concludes that it is because crosswalks give many pedestrians an overly strong sense of security that oncoming cars will follow the signals, and these pedestrians are less likely to look both ways before crossing the street.

This is a WEAKEN question, meaning we are looking for an answer choice that undermines the argument. Let's look at the options:

(A) The overwhelming majority of pedestrians in high-traffic areas cross streets on crosswalks.

Correct. This fact provides a plausible alternative explanation - more pedestrians are hit by cars on crosswalk not because they fail to pay attention, but because more pedestrians cross in crosswalks than elsewhere. This is an example of a false statistical inference - let's say we have 100 people crossing the street, 80 of them use crosswalks and 20 elsewhere. 20 people out of those using crosswalks get hit and 10 of those crossing elsewhere. Looking at absolute numbers it looks like more people get struck using crosswalks -20 vs. 10 but percentage-wise, it is 25% vs. 50%, so one is actually two times more likely to get struck crossing outside the crosswalk in this scenario. Since the difference in absolute numbers is purely due to the fact that most people use crosswalks, it would be improper to conclude that higher absolute numbers are due to their lack of attention.

(B) The number of pedestrians hit by cars has increased in recent years.

Incorrect. This fact is irrelevant as it has no impact on the relationship between pedestrians using crosswalks and those who cross elsewhere.

(C) Pedestrians tend to underestimate the chances that the signals at a crosswalk will malfunction.

Incorrect. This fact strengthens the argument as it provides additional evidence that pedestrians have an overly strong sense of security.

(D) Drivers are most alert to pedestrians who are in or near crosswalks

Incorrect. This tells us how drivers behave, but the author's argument concerns pedestrians' behavior.

(E) Measures intended to promote safety tend to make people less cautious.

Incorrect. This fact strengthens the argument, suggesting that sidewalks are likely to promote a false sense of security.

Does this make sense?

Let me know if you have any further questions.

tomgbean on November 30, 2019

What threw me off A is that it says "in high traffic areas" whereas the stimulus only talks about pedestrians in general that cross at crosswalks. What about pedestrians in low traffic areas, what if more pedestrians are crossing the roads at crosswalks in low traffic areas than there are in high traffic areas?