Do starter motor replacement problems track share of workers who drive to work alone across states?

A weak hint, not a firm finding: across U.S. states, NHTSA owner complaints about starter motor replacement run higher where share of workers who drive to work alone is higher, after adjusting for the makes sold in each state. This is an association across states, not proof that share of workers who drive to work alone causes this repair.

How to read it: Each dot is a state. Further right means more share of workers who drive to work alone; 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 workers who drive to work alone.

What it shows: States with more share of workers who drive to work alone tend to sit higher on the chart across 28 states: a pattern in the data, not proof of cause.

• The 9 states with the most share of workers who drive to work alone (Louisiana, South Carolina, Kentucky, Indiana, Tennessee, Ohio, Missouri, Michigan, Wisconsin): reports of this repair run 14% above what the makes sold there would predict, and 5 of 9 are above expected. The 9 with the least (New York, Massachusetts, New Jersey, Washington, Oregon, Maryland, Colorado, California, Illinois): 2% below, and 2 of 9 are above expected.
• Exceptions: South Carolina, Tennessee and Missouri are among the highest in share of workers who drive to work alone but report below expected; New Jersey (33% above expected) is among the lowest but above expected.
• Split the states into thirds: the third with the least share of workers who drive to work alone runs 2% below what the makes sold there would predict, the middle third 8% above, and the third with the most 14% above. It steps up steadily.
• For share of workers who drive to work alone, after allowing for the 1562 comparisons we ran, luck alone would produce a pattern this strong about 1 time in 5. Take out any single state and the share of workers who drive to work alone pattern still holds.
• Weak spot: compare only states with similar workers who drive alone to work and the pattern keeps about 0% of its strength, so part of it may come from workers who drive alone to work instead of share of workers who drive to work alone.

Where most workers drive alone, each worker puts every commute mile on one car instead of sharing the wear with carpools or transit.

Source: U.S. Census Bureau, American Community Survey 5-year 2019-2023, counties summed to states (B08301), joined to NHTSA owner complaints · file downloaded 2026-10-06