Do control arm replacement problems track share of households with no vehicle across states?

Across U.S. states, NHTSA owner complaints about control arm replacement run higher where share of households with no vehicle is higher, after adjusting for the makes sold in each state. This is an association across states, not proof that share of households with no vehicle causes this repair.

How to read it: Each dot is a state. Further right means more share of households with no vehicle; higher up means more complaints for this repair than expected (1.0 is average). If the dots climb to the right, reports of this repair rise with share of households with no vehicle.

What it shows: States with more share of households with no vehicle tend to sit higher on the chart across 24 states: a pattern in the data, not proof of cause.

• The 8 states with the most share of households with no vehicle (New York, Massachusetts, New Jersey, Illinois, Pennsylvania, Maryland, Connecticut, Ohio): reports of this repair run 31% above what the makes sold there would predict, and 6 of 8 are above expected. The 8 with the least (Colorado, Tennessee, Texas, North Carolina, Arizona, South Carolina, Florida, Georgia): 0% below, and 2 of 8 are above expected.
• Exceptions: New Jersey and Ohio are among the highest in share of households with no vehicle but report below expected; Georgia (36% above expected) is among the lowest but above expected.
• Split the states into thirds: the third with the least share of households with no vehicle runs 0% above what the makes sold there would predict, the middle third 1% above, and the third with the most 31% above. Most of the share of households with no vehicle effect sits in the third with the most.
• For share of households with no vehicle, after allowing for the 1562 comparisons we ran, luck alone would produce a pattern this strong about 1 time in 43. Take out any single state and the share of households with no vehicle pattern still holds.
• Weak spot: compare only states with similar vehicles per household and the pattern keeps about 49% of its strength, so part of it may come from vehicles per household instead of share of households with no vehicle.

Where more households own no car, more people walk, ride transit and drive short trips, so the cars that are owned log fewer miles of stop-and-go wear.

Source: U.S. Census Bureau, American Community Survey 5-year 2019-2023, counties summed to states (B25044), joined to NHTSA owner complaints · file downloaded 2026-10-06