How Many Cars Does a New Apartment Bring?

Enter a ZIP code to see how many vehicles local households own, then test a parking requirement against them.

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Vehicles per household

 

How many vehicles each household has

Share of households

Same ZIP, by household size

Average vehicles at right

Smaller households own fewer cars. That is why the mix of studios and family units matters as much as the neighborhood.

The parking-minimum test

A new building in this ZIP
Who moves in
Code requires, stalls per apartment
Construction cost per stall
Stall audit
Stall a resident’s car is likely to fillStall likely to sit emptyCar with no stall
What it means for parking
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Data as of Vehicles by household size: ACS 5-year, 2020 to 2024, via BTS NTAD (updated April 10, 2026) ZIP areas: Census 2020 ZIP Code Tabulation Areas Stall costs: UCLA ITS, 2025 construction costs (published February 2026)

Source: U.S. Department of Transportation, Bureau of Transportation Statistics, National Transportation Atlas Database, Household Size by Vehicles Available (census tracts), drawn from the Census Bureau’s American Community Survey 5-year estimates, 2020 to 2024; data downloaded October 2026. ZIP figures are built from tracts: each tract’s households are split among the ZIP Code Tabulation Areas it overlaps in proportion to land area (Census Bureau 2020 ZCTA to tract relationship file), so a ZIP’s numbers are estimates, not a direct census count. County and U.S. figures sum whole tracts. P.O. box and business-only ZIPs have no census area.

How the test works: expected cars are the number of apartments times the share of each household size times that size’s average vehicles in this ZIP (the county’s average fills in where a ZIP has too few households of a size). Households with four or more vehicles count as four. The figures cover all households, owners and renters; renters own fewer vehicles than owners, so for a rental building these estimates are generous to the parking requirement. “Mostly studios, 1BR” assumes 60, 30, 7 and 3 percent one-, two-, three- and four-plus-person households; “Family units” assumes 20, 35, 22 and 23 percent. Both are illustrative. Stall costs are 17-city averages for 2025 construction, excluding land, from UCLA’s Institute of Transportation Studies, as cited in Santa Monica’s Height Fight Is Really a Parking Fight. Census estimates carry margins of error, which are widest for small ZIPs.