Question

Argument:
"Cities that invest in cycling infrastructure will see a long-term reduction in traffic congestion because people will shift from cars to bicycles."
Question:
Which of the following is an essential assumption in the argument?

Hint:

Assumptions fill the logical gap between the evidence and the conclusion. Ask yourself: “What must be true for the argument to work?”

Answer 1

Picture the plan failing and ask what single fact, if true, would explain the failure best. If the city builds cycling lanes and congestion simply never improves, the most direct explanation is that nobody who currently drives actually switches to a bike, whether from distance, weather, fitness, or habit. That missing fact — that enough current drivers are both willing and able to switch — is exactly what the argument needs but never states, which is why it counts as the essential assumption; remove it and the plan can fail even with perfect infrastructure. Facts about cycling being healthier or cheaper describe nice side effects, not requirements for congestion to fall, and a comparison to other cities never enters this city's cause-and-effect chain at all, so none of those are essential the way the willingness and ability to switch is.