Every number on this site traces back to a specific statute section, read directly, on a specific date. This guide walks through what that process actually looks like, as a companion to the methodology page — read that page for the short version; this one goes into more of the reasoning behind each rule.
Statute first, agency page only as a fallback
For each state, the child-restraint statute itself is the primary source for every required field: the rear-facing, forward-facing, booster, and belt rules; the front-seat rule; the penalties; and the exemptions. A state agency page is used only when the statute itself doesn’t set a number we need — for example, a general reference to “child passenger safety” without a specific figure — and even then, the agency has to be the one legally responsible for child passenger safety in that state, not just any state website that happens to mention car seats.
Sources that don’t make the cut, ever, as a citation for a published value: law firm articles, car seat retailer buying guides, comparison sites, and general safety blogs. These can be useful as a lead — a hint that a number might be wrong or that a law recently changed — but every value they suggest gets re-read at the statute or agency source before it’s published. IIHS and GHSA tables fall into a related but distinct category, covered below: useful for comparison, never used as the citation itself.
A block without a source doesn’t ship
This is the part that’s enforced mechanically rather than just as a writing standard. Each of the four required blocks on a state page — car seat stages, front seat, penalties, exemptions — has to carry a source URL, a source name, and the date it was verified, or that state’s data doesn’t pass validation. There’s no field for “we’re fairly confident about this one” as a substitute for a citation. A value that can’t be traced to a specific source isn’t published; the field is left out and the state is held back until it can be confirmed, rather than shown with a placeholder or a best guess.
What “not addressed in statute” actually means
You’ll see this phrase, or a close variant of it, on a number of state pages — for the rear-facing stage, the front-seat age, an exemption, or elsewhere. It has one specific meaning: someone read the relevant statute section in full and confirmed it doesn’t set a value for that field. It’s written this way only after that reading has happened, with the section cited alongside it.
It does not mean the source couldn’t be reached, or that nobody has checked yet. A source that can’t be opened is a different situation entirely — that state is held back from publication until someone can read it, rather than marked as if the statute had been read and found silent. The two situations look similar from a reader’s perspective (“no number here”) but come from very different amounts of work, and the site is careful to keep them distinct.
This matters more than it might first seem, because a genuinely large share of the data on this site is exactly this kind of confirmed silence rather than a missing gap. A meaningful number of states, for instance, regulate the rear-facing and forward-facing stages only through a general requirement to use “a child passenger safety seat system” per the manufacturer’s instructions, without ever using the words “rear-facing” or setting an age for it — in those states, the rear-facing and forward-facing fields correctly read “not addressed in statute,” because that’s what a full reading of the relevant section actually found.
How the exit conditions get tagged
Statutes describe when a child can leave a stage in different ways, and a single number can’t always capture the wording faithfully. Every stage carries a tag for how its limits combine, decided by reading the statute’s actual phrasing rather than guessing from the numbers alone:
- Wording joined by “or” between a stay condition — such as “younger than two or under 30 pounds shall ride rear-facing” — is read as requiring both conditions before the child may leave, since the child must fail to meet the stay condition entirely to exit it.
- Wording like “unless taller than four feet nine inches” describes an exit on either condition being met, and is tagged accordingly.
- A single numeric limit, with no second condition, is tagged the same way — met once and the child exits.
- Where a statute mixes conditions in a way neither of those patterns can represent — an age-and-weight test combined independently with a height test, for instance — the full condition is written out in plain terms instead of forced into a shape that would misstate it.
- Some statutes use a fit test rather than a number at all — “until the seat belt fits properly” is the clearest example — and those stages are tagged to show the rule is qualitative, with no number to project.
The statute’s own wording is always shown first on the page. The tag and the numeric summary next to it are a comparison aid, not a replacement for what the law actually says.
Cross-checking against IIHS and GHSA — and why the statute still wins
Every state’s data is compared field by field against the IIHS child safety seat table and the GHSA child passenger safety table after the statute has been read. When our reading disagrees with either or both of those tables, the response is to re-read the statute section our note cites — not to change the value to match the table. If the statute still supports what we recorded after that second read, the statute’s value stays, even in the case where IIHS and GHSA happen to agree with each other. Those tables are valuable for pointing at a section that might be worth a second look; they are never themselves the citation for a published figure.
Verified dates, and why they matter more than they look
Every sourced block carries the date it was last checked against the statute. That date is not a formality — it’s the honest answer to “how current is this,” which is a different question from “is this correct,” because a statute can be amended the day after a page is checked. When a legislature has passed a change that isn’t yet in force, the page shows today’s value as what’s actually in effect right now, with the enacted change and its effective date shown next to it, and the site rebuilds daily so the new value takes over automatically once that date arrives — nobody has to notice and edit the page by hand.
Reporting something that looks wrong or stale
Fifty-one jurisdictions amend their statutes on an ongoing basis, and a site covering all of them will sometimes be behind a recent change. A correction that names the specific statute section is the fastest one to act on — send it through the contact page. The verified date on each block tells you how long it’s been since that section was last read; if it’s been a while and you have reason to think something changed, that’s worth flagging even without the section number.