Estimation question

How long does an average person wait at an intersection?

Practice this question out loud. An AI interviewer asks it, follows up like a real interviewer would, and scores your answer. Type or speak.

What this question tests

Whether you can build a clean estimation from reasonable assumptions and check the answer for sanity.

Clarify scope: average across all intersections, all times of day, one country like the US.
Break it into intersection types: signaled versus stop sign versus roundabout, and estimate the share of each.
Assume signal cycle length, say 90 seconds, with roughly 40 seconds of green and 50 seconds red or yellow for a given direction.
Estimate a person hits a red light roughly half the time they approach a signaled intersection.
Combine: expected wait when hitting red is about half the red duration, so roughly 25 seconds, weighted by the chance of hitting red.
Sanity check: a blended average across all intersection types likely lands between 10 and 20 seconds per intersection.

States assumptions explicitly, for example 90 second cycle and 50 percent chance of arriving on red (assumption).
Shows the math: 0.5 times 25 seconds plus a lower wait for stop signs, blending to a single number.
Arrives at a defensible range, 10 to 20 seconds, rather than a single false-precise number.

Chapters of the AI PM course that teach what this question tests.