How to read a surveillance transparency portal
Vendor transparency pages publish real numbers in a format designed to reassure. Six fields, what each one actually tells you, and the two that matter most.
Several ALPR vendors publish per-agency transparency pages, and FlockDetour indexes them so the map can show more than a location. The pages are genuinely useful — they are also written by the vendor, and reading them well means knowing which fields carry weight.
Here is what you will typically find.
Retention days
How long captured records are kept before deletion. This is the single most informative number on the page. A 30-day window and a 365-day window describe two completely different systems running identical hardware, because retention determines whether the network can answer questions about last week or about last year.
Read it first. Everything else is context for it.
Owned cameras
How many devices the agency operates. Useful for scale, and useful as a cross-check: if an agency's published count is far above the number of documented readers in the same area, the map is behind, not the portal.
External organizations
How many outside agencies or organizations the data is shared with. This is the field most often skimmed and most often decisive.
Sharing is a multiplier on every other number. A strict 30-day retention policy is much weaker if records are replicated to a partner pool where a different — possibly longer — policy applies. An agency with a short window and a large sharing count has, in practice, outsourced its retention policy to everyone it shares with.
Hotlist hits
How often a passing plate matched a watch list. Presented as the system working, and sometimes it is. What the number cannot tell you on its own is the denominator: a hit count means little without the total reads it came from, and the two are rarely shown side by side.
Recent searches
How many queries staff ran in a recent window. This is the one that has driven the most local scrutiny, because searches are the point where a passive record becomes an active look at a specific vehicle. A high search count is not automatically improper — it is the number that makes an audit worth requesting.
Vehicles detected
The raw volume of reads. Mostly a measure of how busy the roads are, and the field least likely to change how you feel about anything.
Reading the page as a whole
Two agencies can publish the same camera count and run completely different surveillance programs. Retention and sharing are where the difference lives.
Transparency pages are a floor, not an audit. They report what the operator chose to publish, in the operator's framing. The genuinely accountable version of these numbers is a public audit log with query justifications attached — which is a records request, not a web page.
FlockDetour links to the original portal on every agency it indexes, unmodified, so you can read the operator's own words rather than our summary of them.