Question 161·Medium·Inferences
Many cities try to reduce traffic by widening highways. However, a longitudinal analysis led by transport economist Mina Ortiz found that within two years of adding lanes, the extra capacity was largely absorbed by new drivers and longer trips, returning congestion to near previous levels. In the same cities, programs that staggered work start times and increased bus frequency reduced peak delays without expanding roads. Therefore, city planners should recognize that ______
Which choice most logically completes the text?
For SAT Reading & Writing “complete the passage” questions, first identify signal words like “Therefore,” “Thus,” or “As a result” to know the blank must reflect a conclusion or explanation. Briefly restate in your own words what the passage has shown right before the blank—especially any contrasts or cause-and-effect relationships. Then eliminate choices that (1) contradict specific evidence, (2) are too extreme (words like “always,” “never,” “regardless”) compared with what’s stated, or (3) introduce new ideas not mentioned. Finally, choose the option that best summarizes the key evidence and matches the passage’s overall direction and tone.
Hints
Locate the key contrast
Focus on how the passage describes the results of widening highways compared with the results of the other programs (staggered work times and more frequent buses).
Use the word “Therefore”
The blank follows the word "Therefore," so it must state the main conclusion or lesson drawn from the study’s findings, not introduce a new idea.
Ask which approach worked better
Based on the study, did simply adding lanes solve congestion in a lasting way, or did the other programs have more success? Choose the option that captures that difference.
Watch out for extremes
Be cautious with answer choices that say something happens "regardless of" any policies or that a certain type of investment is "unnecessary"—check whether the passage’s evidence truly supports such strong claims.
Step-by-step Explanation
Understand what the passage is about
The passage discusses how cities try to reduce traffic by widening highways, then reports on a study that looked at what actually happened after lanes were added and after other types of programs were used.
Separate the two types of strategies
First strategy: widening highways (adding lanes). The study found that within two years, the extra capacity was mostly used up by new drivers and longer trips, so congestion went back to almost the same level.
Second strategy: programs that staggered work start times and increased bus frequency. In the same cities, these programs reduced peak delays without expanding roads.
Infer the main lesson for city planners
The conclusion starts with "Therefore, city planners should recognize that ______." The word "Therefore" signals that the blank must summarize the lesson from the study:
- Simply adding lanes does not give lasting improvements.
- Changing work schedules and boosting public transit did reduce peak congestion. So the takeaway has to express that the second type of strategy works better than the first.
Match each answer choice to the evidence
Evaluate the choices based on the study's results:
- A says congestion worsens no matter what; that ignores the success of the programs that reduced delays.
- B claims adding lanes consistently and lastingly reduces congestion; the passage says the opposite.
- D says transit investments are unnecessary; the passage shows increased bus frequency helped.
- C says that strategies changing when and how people travel can reduce congestion more effectively than just expanding roads. This exactly reflects the contrast between (1) lane expansion that failed and (2) schedule and transit changes that succeeded, so C is the correct answer.