What we can show that nobody else has
We index 10,531 installation points and read the federal crash files ourselves. When that produces something worth publishing on its own, it goes here — with the method attached and the limits stated in the same breath.
Interlock laws and costs in all 51 US jurisdictions
One table: how long the term runs, the reading that locks the car, what the state permits a provider to charge where it says anything at all, and which agency runs the programme — each line with the source and the date we checked it.
Read the analysis →
Drunk driving deaths by county, and the problem with ranking states
County-level rankings of alcohol-involved fatal crashes — and the reason the usual state comparison is misleading: it tracks how often police obtain an alcohol test at least as closely as it tracks drinking.
Read the analysis →
Four states cap what an interlock may cost. The rest let the market decide
Every published fee we could verify, with the rule or filing behind each one — including the assistance several states offer and providers rarely mention. Removing the device costs nothing in Virginia and $150 in Illinois.
Read the analysis →
Take the tables, not just the conclusions
Both files are published under CC BY 4.0. Each row carries the source and the date it was checked, so a claim can be traced without asking us.
| File | Rows | What is in it |
|---|---|---|
| interlock-law-by-state.csv | 51 | The term a first offence carries, the lockout threshold the device is set to, the agency that runs the programme and the date each row was verified. |
| interlock-fees-by-state.csv | 14 | Every jurisdiction that publishes a figure or caps one: installation, monthly monitoring, removal, the type of regulation and the document behind it. |
The rules we hold ourselves to
- Every figure carries its source. Legal claims cite the statute or the agency page, with the date we checked it. Where a source does not support a claim, we cut the claim rather than hunt for a friendlier source.
- Limits stated next to the number, not in a footnote. The crash analysis says plainly what its measure cannot tell you, because that turned out to matter more than the ranking.
- We correct ourselves in public. Running these numbers made us rewrite our own state pages. That is said on the page itself.
- Free to reuse. The federal data is a US government work; our aggregation is yours to cite. Ask if you want a cut we have not published.