$105.93 a month. That's the average car insurance bill in Spring Hill, Tennessee, according to SmartFinancial's 2026 numbers — well under the $169.67 national monthly average and under Tennessee's own statewide full-coverage figure of $2,004 a year.
What makes that number worth a second look isn't the price. It's the city itself. Spring Hill isn't contained inside one county the way Franklin or Murfreesboro are. It sits across a line that splits it between Williamson County and Maury County, and that line matters more to your quote than most residents realize.
One City, Two Rating Territories
Spring Hill grew outward from its original town center until it crossed an existing county line, and it never stopped. Today the city spans both Williamson County, one of the wealthiest and most Nashville-adjacent counties in the state, and Maury County, historically more rural and centered on Columbia to the south.
Insurers price policies partly on territory — a rating zone built from local claims history, not city limits. Williamson County's territory data reflects the low-claim, high-income pattern seen in neighboring Franklin. Maury County's reflects a different mix. Two houses a few miles apart, same zip code, same school district, can land in different territories on an insurer's rate sheet.
A Boomtown Insurers Are Still Pricing
Spring Hill had fewer than 30,000 residents in 2010. It passed 41,000 by 2020, crossed 53,000 the following year, and sits above 56,000 now — one of the fastest population run-ups of any city in the country over that stretch, and a repeat entry on national fastest-growing-city lists.
Rating territories are built on historical claims data, and historical data lags a city that's adding thousands of residents a year. That gap cuts both ways: it can mean Spring Hill's low rate hasn't caught up yet to newer traffic patterns, or it can mean a driver who just moved in is still quoted off an old territory read that doesn't reflect the subdivisions built in the last two years.
The GM Plant's Steady, Predictable Traffic
The city's modern identity traces back to General Motors, which opened its Spring Hill plant in 1990 — a 7.9-million-square-foot facility on about 2,000 acres that today builds the Cadillac XT5, XT6, and the electric Lyriq. It employs more than 3,200 workers directly.
A plant that size means shift-change traffic clustering at predictable hours around the facility and the roads feeding it. That kind of dense, low-speed volume tends to generate parking-lot dings and fender-benders rather than serious collision claims — real, but not enough to push Spring Hill's average above the state's.
Low Crime Helps Keep the Average Down
Spring Hill's overall crime rate runs about 57% below the national average, and its vehicle theft rate is a small fraction of the national figure. Fewer comprehensive claims from theft and vandalism is one of the clearest reasons the city's premium sits below the statewide number despite its rapid growth.
Commutes add a counterweight. Average commute times run around 32 minutes, with the WeGo Park & Ride service offering an alternative for residents heading into Nashville rather than driving the full distance themselves. That's more time on the road than a typical small town, even if it isn't enough to erase the low-crime discount.
What This Means for Your Policy
- Check which county your address rates under: a Williamson-side and Maury-side quote can differ even within Spring Hill.
- Don't assume your old city's rate applies here: newcomers to a fast-growing city can be quoted off outdated territory assumptions.
- Keep UM/UIM matched to your liability limits: Tennessee's statewide uninsured-driver rate near 21% applies here regardless of county.
- Get more than one quote: territory-rating differences mean shopping around matters more in a split city than in a single-county suburb.
Not sure how your current limits stack up against what you actually need? Our guide to comparing car insurance quotes walks through what to check beyond the headline price.