Methodology
Every Safe Trip Score is reproducible from raw events, a versioned algorithm, and a signed editorial override layer. We show our work, so press, regulators, and B2B procurement teams can audit the number on the page.
Six sub-scores, weighted
Each country is recomputed daily from the events of the past 90 days, weighted into six sub-scores. The overall score is a weighted blend, then nudged by ±20% toward the average of available government advisories.
overall = Σ (sub_i · weight_i)
overall = overall · (1 − 0.20) + advisoryAvg · 0.20
overall = clamp(overall + editorialDelta, 0, 100)Signal confidence tiers
Every event is tagged with a confidence tier. Higher tiers carry more weight; tier-1 sources can override the rest.
- Official
WHO, ECDC, USGS, NOAA, GDACS, national authorities, government advisories.
- Confirmed news
Reuters, AP, AFP, ACLED, corroborated by multiple desks.
- Unverified
ProMED tip, social, regional outlet without corroboration. Lower weight, never headline driver.
How each sub-score sources its data
Each of the six categories has a primary feed plus a long term baseline that holds when no recent event is active. We’re honest about which categories have which.
- Disease
WHO Disease Outbreak News + CDC Travel Health Notices. Real-time outbreak ingestion; events decay over 60 to 90 days.
- Disaster
USGS earthquakes (live geo-JSON) + GDACS floods, wildfires, volcanoes, tropical cyclones.
- Crime
UNODC intentional homicide rates per 100,000 population (annual baseline, baked from the World Bank’s public mirror of UNODC data). Refreshed annually.
- Infrastructure
WAQI / aqicn.org for current PM2.5 air-quality readings; events written when readings cross EPA “Unhealthy for sensitive groups” (AQI 101+). Future: Eurostat industrial-action data.
- Conflict & civil unrest
Currently advisory-driven: there is no primary source event feed populating these two sub-scores today. Long-term baselines hold by default; the 20% government-advisory blend captures real time movement when ministries raise their levels in response to active conflict or unrest. ACLED is the industry standard but requires a paid commercial tier we haven’t taken on yet, when revenue justifies it, ACLED will plug straight into the existing event pipeline.
- Government advisories (blended at 20%)
UK FCDO · US State Department · Smartraveller (AU) · travel.gc.ca · Auswärtiges Amt · France Diplomatie. Six ministries, daily refresh, normalised to a common 1 to 4 level scale.
Editorial overrides
Some signals require human judgement. A wildfire in central Portugal does not affect Lisbon; an outbreak in one province does not collapse a country score. Editorial reviewers may apply a calibrated delta, capped at ±25 points, and every override is signed, time-bound, and visible on the country page.
Versioning & reproducibility
Algorithm versions are immutable once published. Major changes carry 14 days of notice on the changelog. Pro and B2B users can pin a specific version for their reports, the full version manifest (weights, decay windows, source list) is downloadable JSON.