Sources and method

State rules

Each state page is written from the state's own pages: the DMV, the environmental agency, the program's official site or the legislature. For every fact we keep:

• a short summary in plain English;
• the agency's own words, quoted exactly;
• the link to the page and the day we checked it.

We save the text of every source page when we check it. The site cannot be built if a quotation is not word for word in that saved text, or if our summary uses a number the quotation does not contain. A state page with a live program is indexed by search engines only with at least 4 verified facts across 3 topics, including where or which vehicles; a page whose newest source check is more than 365 days old drops out of search until it is checked again.

34 state pages cite 52 saved source pages. A few agencies refuse automated requests from our build machine; for 19 of those pages the text was retrieved through a public reading service that fetches the same public page, and the record says so. Where we found no official source for a rule (a fee, say), the page leaves it out rather than guessing.

After that word-for-word check, every fact gets a second read against the source sentence around the quotation: a quotation that starts in the middle of a sentence or refers back to one (“vehicles in this category”) is quoted with the sentence it depends on, a list of exemptions is either quoted in full or introduced as “exemptions include”, and where a loosely worded FAQ and an agency explainer differ, the explainer wins. A fact tied to a date (a program that starts on a given day, a schedule for one registration year, a pending federal approval) carries the last day it may be shown as written; after that day the site cannot be built until the fact is checked again.

Some state pages are kept out of search engines although their facts check out: Florida, Michigan, Tennessee, Texas. Texas is a short summary of the state agency's overview. For the others, the only official statement we hold comes from another state's list of states without testing, and we want the state's own statement before the page is indexed.

New York station data

Two public datasets from the New York State DMV on data.ny.gov: Vehicle Inspections (one record per inspection since 2021-08) and Facilities Licensed by the DMV (stations, addresses and license dates). We add the inspection records up per station and month with database queries on the portal, without downloading the individual records, and join them to the license list on the DMV facility number. Inspection data checked Oct 6, 2026; license list checked Oct 6, 2026. Figures cover the 12 months Sep 2025 to Aug 2026.

• Inspections: every record, initial inspections and re-inspections.
• Fail rate: initial inspections whose first emissions result was FAIL, divided by initial inspections with an emissions result (PASS, FAIL or STOP). STOP is reported separately, as the DMV records it.
• OBD share: initial inspections that were on-board diagnostics (OBDII) tests, divided by all initial inspections.
• Rates are shown only above 200 emissions tests.

Which stations get a page

Every station with a current license is listed on its county page and in the finder. A station gets a page of its own only when its license is current on the day the site is built, it recorded inspections in each of the last 3 months, it did at least 2,000 initial inspections and 500 initial emissions tests in the 12 months, and it ranks among the 2,500 busiest such stations. Today 1,408 of 8,045 stations qualify. Search demand for individual station names is close to zero, so a station page has to earn its place with numbers large enough to mean something; for now only the 254 station pages with at least 5,000 initial inspections are offered to search engines, and the others stay available from their county page and the finder.

County pages are indexed with at least 5 active stations. Town pages exist for towns with at least 15 stations; a town that holds 50% or more of its county's stations gets no page of its own, because the county page already lists the same stations (Rochester keeps its page: people search for it by name).

What the numbers do not say

A fail rate is not a rating. It depends on the age and condition of the vehicles a station inspects, on the mix of tests it does and on where it is. We show no hours, prices or reviews for individual stations, and no station pays to appear.

Corrections

Found something out of date? See corrections or write to contact@emissionstesting.net.