EMS dispatch transcripts vs. SWITRS official records
This map tracks bicycle and pedestrian collisions in El Cerrito, Richmond, Albany, and Berkeley — comparing official SWITRS records against EMS dispatch radio transcripts to measure how many crashes go unreported.
SWITRS (currently shown) — California's official Statewide Integrated Traffic Records System, exported from tims.berkeley.edu. Covers only crashes that were reported to law enforcement.
EMS Dispatch (limited data — still processing) — extracted from Broadcastify scanner archive recordings using Whisper transcription and Claude, plus news reports. Reveals crashes that were responded to by EMS but never filed as police reports.
About 40% of SWITRS records lack GPS coordinates and are geocoded using Claude (address normalization) and the Google Maps API. Geocoded incidents are validated against a West Contra Costa bounding box.