After the rush-hour speed limit on the British M25 motorway was lowere

Question

After the rush-hour speed limit on the British M25 motorway was lowered from 70 miles per hour (115 kilometers per hour) to 50 miles per hour (80 kilometers per hour), rush-hour travel times decreased by approximately 15 percent.

Which one of the following, if true, most helps to explain the decrease in travel times described above?

(A) After the decrease in the rush-hour speed limit, the average speed on the M25 was significantly lower during rush hours than at other times of the day.

(B) Travel times during periods other than rush hours were essentially unchanged after the rush‑hour speed limit was lowered.

(C) Before the rush-hour speed limit was lowered, rush-hour accidents that caused lengthy delays were common, and most of these accidents were caused by high-speed driving.

(D) Enforcement of speed limits on the M25 was quite rigorous both before and after the rush‑hour speed limit was lowered.

(E) The number of people who drive on the M25 during rush hours did not increase after the rush‑hour speed limit was lowered.

LSAT

Vinodsai1995 · Answer

C is the answer imo as it talks about time delays due to accidents

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pkshankar · Answer

We need to address the paradox in this question.
Even though the speed limit was lowered from 70mph to 50mph, travel times decreased.
One would expect travel time to increase but on the contrary it decreased.
Only option C addresses the paradox by stating that the reduction of speed limit reduced the no. of accidents which were the reason behind time delays earlier.

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Catman · Answer

In general if the speed is reduced, the time has to increase for the same distance to be covered. In this question we have to resolve the paradox " Reduction in rush-hour speed, results in reduction in rush hour travel time."

(A) After the decrease in the rush-hour speed limit, the average speed on the M25 was significantly lower during rush hours than at other times of the day.  ~ Reduction in the lower rush hour speed will increase the time. This does not resolve the paradox.

(B) Travel times during periods other than rush hours were essentially unchanged after the rush‑hour speed limit was lowered.  ~ Argument is about the rush-hour travel times. We are not concerned with other than rush hours.

(C) Before the rush-hour speed limit was lowered, rush-hour accidents that caused lengthy delays were common, and most of these accidents were caused by high-speed driving.  ~ Correct, the earlier delays were due to the increased waiting time in traffic, caused by rush-hour accidents. Now these accidents are minimized so there is negligible waiting time. This resolves the paradox why the reduction in rush-hour speed, resulted in reduced rush-hour travel time.

(D) Enforcement of speed limits on the M25 was quite rigorous both before and after the rush‑hour speed limit was lowered. ~ This may be true, but does not resolve the paradox mentioned in the argument.

(E) The number of people who drive on the M25 during rush hours did not increase after the rush‑hour speed limit was lowered.  ~ If the number of people who drives during the rush hour remains same than the time should be increased.

After the rush-hour speed limit on the British M25 motorway was lowere

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