38.4.14 "Reducing speed limits neither saves lives..." Forum

[WaltGrace83]

Am I wrong for thinking that this question is awful?

• More slowly car is driven = more time it spends spewing exhaust
  +
  More slowly car is driven = more more time running risk of collision
  →
  Reducing speed limits neither saves lives nor protects environment

The first flaw that I see is that maybe more time does not necessarily equal more pollution (or whatever you'd say is bad for the environment). Perhaps the more slowly you are driving the less pollution because of whatever reason. In addition, I see that there is a disconnection between cars driving "more slowly" and "reducing speed limits." Maybe speed limits will be reduced but the speed of cars may not (this happens all the time in the real world). So I go into the questions armed with these two flaws.

I have no problem with (B), we don't need to know anything else besides simply "saving lives" and "protecting the environment." (C) is also ridiculous because we have no idea how having more cars on the road will affect safety or emissions. (E) is wrong because "only if." The argument is simply not assuming this.

My problem (confusion?) is with (A) and (D). (D) gets at flaw #1 (time vs. emissions) while (A) gets at flaw #2 (more slowly and reducing speed limits).

(D) the author simply does not assume that total emissions of a trip are determined primarily by the amount of time, right? The only thing I could say is that, since the conclusion is so strong, the author assumes that the time is also very significant. I'm just not sure.

(A) is this wrong simply due to strength? "Some" is a very weak word and we cannot really tell if the author is doing this or not. However, even if the author IS neglecting "some" drivers that completely ignore speed limits, is this necessarily a bad thing? Is this necessarily a flaw, if the author is still assuming that a significant amount of people DO obey the speed limit?

If someone can help me see where my thinking falls short, I'd appreciate it.

[Rhymes With Wolf]

So we're looking for what's wrong with the argument. Maybe something else factors into the amount of exhaust spewed (maybe the rate of spewing matters more than the time spent spewing), maybe the collisions that occur driving slowly don't result in the same loss of life as high-speed collisions, and it assumes that "more" (at least one) cars will adhere to the new, lower speed limit. If even one car spends more time spewing exhaust or runs a higher risk of collision, but everyone else ignores it by speeding, then the net impact is negative and the limit has done nothing to save lives or protect it.

With (A), we're not so sure the author has even ignored this fact. He could have accounted for some (weak) motorists ignoring it, hell even most motorists could be ignoring it, because all his argument takes is "more" cars behaving as he described. Even if he didn't account for some, it's such a vague choice that it doesn't really have a bearing on his argument. It would take every car ignoring the limit (and, even then, ignoring it by driving faster) for the argument to be flawed.

(D) is exactly one of the flaws we identified. Maybe car engines release emissions exponentially at higher speeds due to engine temperature or inefficiencies, for example.

[WaltGrace83]

So we're looking for what's wrong with the argument. Maybe something else factors into the amount of exhaust spewed (maybe the rate of spewing matters more than the time spent spewing), maybe the collisions that occur driving slowly don't result in the same loss of life as high-speed collisions, and it assumes that "more" (at least one) cars will adhere to the new, lower speed limit. If even one car spends more time spewing exhaust or runs a higher risk of collision, but everyone else ignores it by speeding, then the net impact is negative and the limit has done nothing to save lives or protect it.

With (A), we're not so sure the author has even ignored this fact. He could have accounted for some (weak) motorists ignoring it, hell even most motorists could be ignoring it, because all his argument takes is "more" cars behaving as he described. Even if he didn't account for some, it's such a vague choice that it doesn't really have a bearing on his argument. It would take every car ignoring the limit (and, even then, ignoring it by driving faster) for the argument to be flawed.

(D) is exactly one of the flaws we identified. Maybe car engines release emissions exponentially at higher speeds due to engine temperature or inefficiencies, for example.

Thanks! I see your point and I absolutely agree that "some" is weak. However, I am more concerned with the word "PRIMARILY" in (D). That seems too strong.

[Tyr]

I didn't think this one was so bad. This is how I went about solving it...

1. Read the passage and find the conclusion.
C: You won't protect the environment or save lives by reducing the speed limit.

2. What's the problem between the support and the conclusion? What is the specific flaw?
Flaw: It seems to be that the author is assuming that the emissions/collisions are directly linked to the amount of time on the road without giving any information of vehicle performance at different speeds or anything else that would indicate that time is the central reason for making this conclusion. It's a Causal Flaw in that the amount of time is what causes the amount of pollution/collisions. Maybe something else causes the amount of pollution/collisions to increase/decrease.

3. Pre-phrase an answer.
A: The author assumes time on the road is THE determining factor in level of pollution - that there isn't some other element that has an equally or greater role in this problem.

4. Let's get our guns and go huntin'!
A. Who cares about ignoring speed limits. Eliminate.
B. We're not talking about benefits here. Eliminate.
C. Number of cars on the road? We can't make an assumption here that more cars means more pollution or collisions. Eliminate.
D. Ah ha! This sounds a lot like what we had thought up before even looking at the answers. Keep it.
E. So this is saying if there is a significant risk of collision, then they are spending a lot of time on the road. Way wrong. Eliminate.

Stay focused on the task at hand and it becomes so much easier to find the one correct answer and not get distracted by all that noise.

[Rhymes With Wolf]

Thanks! I see your point and I absolutely agree that "some" is weak. However, I am more concerned with the word "PRIMARILY" in (D). That seems too strong.

The author has concluded that emissions will not be reduced due to the amount of time trips will take. To conclude that, the author must assume that no other factors mitigate the impact of the increased emissions due to slow speeds. This means he has to treat it as the primary factor. This is why it's a flaw, he's assuming it's the most important factor, and therefore single-handedly determining net emissions, without providing justification.

[akechi]

I eliminated (A) because, even if he/she considered it, it would strengthen the conclusion. If some motorists completely ignore speed limits, then it seems to add evidence for the conclusion that reducing speed limits neither saves lives nor protects the environment. I understood it as implying that there are some people that simply do not even pay heed to the sign, which means it [speed limits], in some cases, aren't really doing anything at all - in regards to saving lives or protecting the environment.

It would be like saying: "The surgeon general's warning on cigarettes does not save lives" and someone trying to counter that statement with "Well, you overlook the fact that some people don't even look at the warning". In this case, I think it is more evident why it would be a potential strengthener. Further, this objection is actually compatible with the conclusion.

As far as (D) is concerned, I think this assumption warrants the use of "primarily". Looking at the conclusion:

C: Reducing speed limits does not protect the environment.
P: More slowly a car is driven, the more time it spends on the road spewing exhaust into the air.

Analysis: It's fair to grant that the more slowly a car is driven equates to more time spend on the road, and thus more time spent on the road spewing exhaust into the air (but how much exhaust? Is time the only factor in determining amount of exhaust?). Taking these statements at face value, he concludes that this does not protect the environment. In order to conclude that, he must be assuming that more time = more exhaust. But what the author fails to consider is that there could be other equally relevant factors that determine the total amount of exhaust released, for example, speed (as others have mentioned). What if driving more slowly + spending more time on the road actually reduces the amount of exhaust released, as compared to driving faster + spending less time on the road?

Accordingly, because the author has neglected to entertain these other plausible alternatives, he is presuming, without providing justification that "total emissions for a given automobile trip are determined primarily by the amount of time the trip takes". In other words, the "presuming, without providing justification" is referring to the fact that the author has not sufficiently established that time is in fact the primary / most significant factor, because, via the hypothetical situation above, we showed that other factors could play a determinative role in establishing how much exhaust is emitted.

Edit: Rhymes_With_Wolf did a far more succinct job of explaining the same thing.

[WaltGrace83]

Ah, so I think I got this. It is really the strength of the argument's conclusion that elicits the strength of the answer choice.

This is different than say, PT30 S2 Q25 (#270 in the Cambridge FLAW Packet). That argument has a really weak conclusion, "We can conclude then that testosterone tends to promote, and estrogen tends to inhibit, heart disease" The answer choice (A) is wrong because the author is NOT saying this. He is NOT saying that these hormones are the PRIMARY factors - only that these hormones TEND TO promote or TEND TO inhibit. This is also the same reason why (B) is wrong.

However, in 30.2.25, if the conclusion was much more strong, like "Testosterone causes heart disease while Estrogen inhibits heart disease," we might say that the author IS assuming the significance of testosterone and estrogen. After all, regardless of everything else, the author says the presence of testosterone is enough to cause heart disease. Would (A) be correct had this been the conclusion for 30.2.25?

Thanks guys and girls.