Break the problem into supply and demand components: estimate the number of parking spots from both public and private sources, then validate with a top-down approach using population and vehicle ownership. Clearly state assumptions and use round numbers to simplify calculations.
Pro tip: Show that you understand the difference between on-street and off-street parking, and mention that the answer depends on definitions (e.g., legal spots vs. informal spots). Also, relate the estimation to product metrics like utilization and user pain points.
Ask clarifying questions to define what counts as a parking spot (e.g., public vs. private, on-street vs. off-street, legal vs. informal). Confirm whether the question refers to the entire city or a specific area.
Decide between a bottom-up (supply-based) or top-down (demand-based) approach. For a city, a top-down approach using population and vehicle ownership is often simpler.
Use known data: San Francisco population (~900k), average household size (~2.5), vehicle ownership rate (~0.5 cars per person), and typical parking ratios (e.g., 1.5 spots per car).
Compute the estimate (e.g., 900k * 0.5 = 450k cars; 450k * 1.5 = 675k spots). Sanity-check against known facts (e.g., SF has ~275k on-street spots, so total including off-street could be ~500k-700k).
Relate the estimate to product management: parking scarcity, potential for digital solutions, and metrics like utilization rate or time-to-park.
AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.