ALPR camera maps:
data, limits, and route checks.

What is an ALPR camera?

An automatic license plate reader is a camera system designed to capture license plate identifiers from vehicular traffic. The OpenStreetMap ALPR documentation notes that systems may also collect vehicle characteristics and that ALPR equipment often uses features such as infrared imaging for low-light operation.

An ALPR camera location alone does not explain who can access the data, how long it is kept, or where it is shared. Those questions require operator policies, contracts, public records, and oversight documents. RouteFrame therefore treats map location, operator, and manufacturer as separate facts.

Where does the ALPR map data come from?

RouteFrame uses the official DeFlock project, which describes itself as a crowdsourced tool for locating and reporting ALPRs. DeFlock uses OpenStreetMap data for camera locations, types, and viewing direction. RouteFrame preloads the available national source snapshot, then requests a current geographic corridor when a route is selected.

The interactive map also queries DeFlock's public Overpass service for OpenStreetMap records tagged as video cameras or gunshot-detector microphones. Users can filter ALPR, video, and audio points independently. These broader layers do not alter the ALPR-only route-footprint calculation.

How RouteFrame checks a driving route

RouteFrame keeps route generation and ALPR evaluation separate so a public-data outage does not fabricate a safe result.

1. Search deliberately.Location suggestions begin after four typed characters and a short pause, not on every keystroke. A deliberately submitted search can fall back to OpenStreetMap Nominatim.
2. Choose exact matches.The user confirms the correct origin and destination instead of RouteFrame silently guessing among multiple places.
3. Build normal routes.Project OSRM returns real driving alternatives, geometry, distance, duration, and turn steps.
4. Load the corridor.The Cloudflare Worker requests DeFlock records around the returned route bounds and preserves source links.
5. Measure proximity.Route geometry is divided into distance-weighted spans of no more than 50 meters. A span is marked near a public record when a loaded ALPR point falls within 55 meters.
6. Measure record spacing.Matched records are projected onto the selected route geometry, ordered from the route start, and reported with along-route gaps. Contiguous matched spans become proximity zones, not prescribed reroutes.
7. Try lower documented exposure.After the standard route loads, the user can request another driving route based on nearby loaded ALPR records. This preference does not certify a camera-free route.

What the nationwide county layer measures

The optional county layer downloads the current DeFlock regional ALPR cache and performs a point-in-polygon join against January 1, 2025 Census TIGERweb county-equivalent boundaries. It includes all 3,235 published county equivalents in the source boundary layer, including counties with no matched public record.

Color represents mapped-record count. The county receipt reports records per 100 land square miles and median nearest-record spacing when at least two points are available. These are source-availability measurements. They do not estimate camera field of view, road coverage, current operation, or the percentage of people observed.

What an ALPR camera map can and cannot prove

ALPR operator versus manufacturer

The OpenStreetMap surveillance guide defines the operator as the organization operating the cameras or controlling the images. Manufacturer and brand tags describe the equipment provider. A Motorola Solutions or Flock Safety vendor tag does not, by itself, identify a police department, municipality, homeowners association, or private owner.

RouteFrame reports operator-tag coverage and vendor-tag coverage separately. If a matched record contains only manufacturer data, the operator remains missing. This prevents a common data-quality mistake from becoming a false ownership claim.

How much does a Flock camera cost taxpayers?

There is no honest single price for every mapped camera. Public contracts can bundle hardware, software, cellular service, installation, maintenance, storage, search tools, support, and optional retention. RouteFrame therefore uses a visible, reproducible sample instead of claiming a nationwide total.

The five official city records below describe 151 cameras and $454,500 in recurring annual spending. That produces a weighted sample of about $3,010 per camera per year. It is a contract-spending estimate, not an exact invoice for any OpenStreetMap node and not Flock Safety's complete government revenue.

City of Hayward: the $202,000 figure above covers the existing 64-camera network only. A separate $392,560 figure in RouteFrame's procurement records covers that same network plus a proposed 30-camera expansion and one year of data retention. The two figures describe different scopes and are not directly comparable.

What to do when ALPR records appear near a route

A public map is a starting point, not the final authority. Use the source record, then request authoritative information from the responsible city, town, agency, or private organization.

• Open the source. Check the OSM node, mapped tags, location, and update history.
• Separate evidence. Distinguish a documented operator from a vendor or visually identified brand.
• Ask for policy. Request locations, contracts, retention, access, sharing, audits, complaints, and corrective actions.
• Use public process. Find upcoming meetings, hearings, procurement votes, and public-comment opportunities.
• Document the response. Keep the tracking number, response deadline, produced records, and any denied portions.

After a route check, RouteFrame creates a ready-to-edit municipal transparency draft and helps find the official clerk or council contact. Verify the government address before sending.