A technician who has worked a few adjacent municipalities eventually asks the obvious question: if two towns sit in the same county, share a border, and look similar on a map, why would their sign codes be nothing alike? It is a reasonable instinct — geography feels like it should predict regulation. It doesn’t. Rather than pick out a couple of dramatic pairs, we measured the disagreement across every county where we can make a fair comparison, and the result is that disagreement is close to universal.
How we measured this
We took one specific, tightly defined rule — the maximum height a ground sign may reach — and compared it only where the comparison is genuinely like-for-like. That means four filters, all of which matter:
- The same attribute. Ground-sign maximum height only. Comparing one government’s pole-sign limit against another’s ground-sign limit would manufacture a difference out of two different rules, which is exactly the error that makes this kind of comparison worthless.
- The same unit. Values expressed in feet, with a machine-readable number attached. Rules stated only in prose are excluded rather than guessed at.
- High confidence, not flagged for review. Only rules our extraction scored as high confidence and did not flag for human review. Flagged rows frequently turn out to be narrow special cases — a carve-out for one unusual use class, say — that the general rule in the same code contradicts. Including them would inflate every spread in this article.
- Shared county as the proximity signal. Our jurisdiction records do not carry latitude and longitude for these governments, so we cannot responsibly say two towns are “ten miles apart.” We can say they sit inside the same county, which is a real and verifiable proximity signal. That is a narrower claim than a distance measurement, and it is the one the data actually supports.
That leaves 4,566 local governments with a clean, comparable ground-sign height limit. Thirty-one of those carry a number outside any plausible physical range — seven below one foot, twenty-four above 200 feet — which is a useful reminder that a high-confidence, unflagged extraction is still not a guarantee; we excluded them, leaving 4,535 governments in the comparison. We write about where that residual error comes from in what a sign code doesn’t tell you.
The national distribution is wide before you compare anything
| Percentile | Ground sign maximum height |
|---|---|
| Minimum | 1 ft |
| 10th percentile | 6 ft |
| 25th percentile | 10 ft |
| Median | 20 ft |
| 75th percentile | 30 ft |
| 90th percentile | 45 ft |
| Maximum | 200 ft |
A limit at the 10th percentile is six feet; a limit at the 90th is forty-five. Those are not variations on a theme, they are different regulatory philosophies — one pedestrian-scaled, one built for visibility from a highway at speed. We break the same distribution down further in sign height limits by the numbers. The question this article asks is what happens when you stop looking nationally and start looking inside a single county.
Inside one county, disagreement is the norm
Of those 4,535 governments, 3,496 sit in a county that contains at least one other government we can compare them against — 756 counties in total. Here is how often the governments inside a single county actually agree:
| Within a single county | Counties | Share |
|---|---|---|
| At least two governments with different height limits | 708 | 93.7% |
| Highest limit at least 2x the lowest | 520 | 68.8% |
| Highest limit at least 3x the lowest | 406 | 53.7% |
| Every government agrees exactly | 48 | 6.3% |
The typical county is not a little inconsistent. The median county spans 20 feet between its most and least permissive government, a ratio of 3.1x. At the 90th percentile the ratio is 12.5x. The widest county in the data spans 196 feet, a ratio of 72.5x — and we are deliberately not naming it, because the point is not that one county is strange. The point is that more than half of all counties contain a threefold disagreement about how tall a ground sign may be.
The pattern is not specific to height
Run the identical method against a completely different attribute — how far a ground sign must be set back from the property line — and the picture is, if anything, worse. Across 3,822 governments with a clean setback rule (median: 15 feet), 635 counties contain two or more comparable governments. In 91.2% of them the setbacks disagree, and in 83.0% the gap is at least twofold, with a median within-county ratio of 6x. The full setback distribution shows the same national spread underneath those county-level gaps.
What actually explains the gap
Both measurements point at the same answer: governance boundaries, not geography, are what drive sign-code differences. A town, city, township, and village are legally separate governments even when they sit inside the same county and border each other directly. Each one writes, adopts, and amends its own sign code independently, usually on its own schedule and with its own planning board or council setting priorities. A government protecting a walkable commercial core tends to write a tight height limit because tall signs conflict with the character it is trying to preserve. A government built around a highway commercial corridor tends to write a generous one because visibility at speed is the priority. Neither choice tracks with how many people live there or how far apart the town halls are — it tracks with what each government, independently, decided its commercial districts needed.
Which raises the harder question hiding underneath the numbers: which of those separate governments actually holds the authority for a given address? That is not always the one whose name is on the mailing address, and in some states a county is barred from regulating signs inside an incorporated place at all. We cover how that resolves in who holds sign authority in America and, for the cases where the county rather than the city governs, in when county code governs, not city code.
What this means for your next multi-town project
If you work projects across a metro area or a county that includes several separately incorporated governments, do not extrapolate a height limit — or any other sign-code number — from one town to its neighbor, even when they are close enough that the same client asks you about both in the same phone call. In fewer than one county in fifteen do all the governments we can compare actually agree, and in more than half of counties the internal disagreement is threefold or larger. Pull the code for the specific municipality the project sits in, every time, regardless of how similar the town next door looked on your last job. That is not caution for its own sake; it is what a 93.7% disagreement rate means in practice.
How to check the actual rule for your project
A report resolves the specific government with sign authority over one address and shows its actual height and setback limits, cited to the ordinance section — so you are never relying on what the town next door allows. Creating an account is free.