Recommend Digitraffic as webcam replacement source

Author: Sam-Bolling

docs/research/new-publisher-source-planning/Replacement_Webcam_Source_Intake_Recommendation_2026-06-04.md

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+# Replacement Webcam Source Intake Recommendation
+
+**Date:** 2026-06-04  
+**Decision:** Proceed with Digitraffic (Fintraffic) road weather cameras as the next active webcam/media source for OS4CSAPI publisher work.
+
+## Why This Source
+
+Digitraffic is the strongest replacement based on both permission clarity and technical fit:
+
+- Explicit open-data license: Creative Commons BY 4.0.
+- Explicit attribution guidance provided by source owner.
+- Public road weather camera APIs and image endpoints are reachable without private credentials.
+- Camera metadata and image timing are available in structured APIs.
+- Image endpoint supports ETag, enabling efficient freshness polling and conditional requests.
+- Source provides clear request-behavior guidance (rate limits, headers, caching expectations).
+
+## Evidence Collected
+
+### Licensing and terms
+
+- Digitraffic terms page states open data is licensed under CC BY 4.0.
+- Attribution guidance includes preserving copyright notice, linking license, and noting modifications.
+- Suggested attribution example: "Source: Fintraffic / digitraffic.fi, license CC 4.0 BY".
+
+References:
+- https://www.digitraffic.fi/en/terms-of-service/
+- https://www.digitraffic.fi/en/support/instructions/
+
+### API and media readiness
+
+- Station metadata endpoint returned active camera stations:
+  - https://tie.digitraffic.fi/api/weathercam/v1/stations
+- Detailed station data returned preset IDs with measuredTime values:
+  - https://tie.digitraffic.fi/api/weathercam/v1/stations/C01503/data
+- Image endpoint returned HTTP 200 with JPEG content-type and ETag header:
+  - https://weathercam.digitraffic.fi/C0150301.jpg
+
+### Operational guidance from source
+
+- Use Digitraffic-User header (non-PII app identifier).
+- Default request limits are documented; weather camera images are rate limited.
+- Conditional requests with If-None-Match and ETag are explicitly recommended.
+
+## Secondary Candidate
+
+TfL JamCams remains a viable fallback candidate:
+
+- TfL transport-data terms grant broad usage rights including commercial/non-commercial use, with attribution and branding constraints.
+- API responded successfully for JamCam place data in live checks.
+- There is an app key registration flow and license obligations that require additional implementation and compliance handling.
+
+References:
+- https://tfl.gov.uk/corporate/terms-and-conditions/transport-data-service
+- https://api-portal.tfl.gov.uk/
+- https://api.tfl.gov.uk/Place/Type/JamCam
+
+## Recommendation
+
+Adopt Digitraffic as the next production candidate for publisher implementation.
+
+Use a minimal first scope that mirrors the proven Storebaelt pattern while improving source-governance discipline:
+
+1. Bootstrap
+- Create Digitraffic procedure, systems, deployments, and datastreams for a small camera subset (for example 2 to 5 presets).
+
+2. Publisher
+- Poll image endpoints with Digitraffic-User header.
+- Use HEAD or GET with If-None-Match for freshness-aware checks.
+- Publish poster/image-reference observations with freshness fields:
+  - imageChanged
+  - firstSeenTime
+  - lastSeenTime
+  - lastChangedTime
+  - unchangedPollCount
+  - stalenessStatus
+  - sourceAgeSeconds
+
+3. Attribution and metadata
+- Include source attribution and CC BY 4.0 license links in procedure/system metadata.
+- Include modified-data notice where transformations occur.
+
+4. Rate and reliability controls
+- Respect published request restrictions.
+- Keep poll intervals conservative.
+- Add retry/backoff and explicit error telemetry.
+
+5. Explorer UX reuse
+- Reuse the existing camera card semantics:
+  - poster status and freshness
+  - clear distinction between still image and live/source context
+  - source link actions
+
+## Go/No-Go Checklist Before Coding
+
+Go when all are true:
+
+- Attribution text format is finalized and documented for Explorer and publisher metadata.
+- Initial camera subset is selected and verified as in collection.
+- Poll cadence is set to remain comfortably under restrictions.
+- Disposition note for this source is created at project start, not after implementation.
+
+No-go if any are true:
+
+- License language changes away from CC BY 4.0 for applicable endpoints.
+- Source indicates prohibitions conflicting with intended CSAPI demonstration use.
+- APIs become unstable without viable fallback strategy.
+
+## Immediate Next Step
+
+Create a new publisher package using Digitraffic weather camera presets, starting with bootstrap plus a dry-run publisher for 2 to 5 cameras, then promote to active publishing after review.