TTDI Solo-Safety Index — methodology
Ranked from TTDI editorial judgments — each city's score is grounded in cited authoritative sources and reviewed under TTDI's audit gates.
The ranked metric
Each city carries a 0–10 solo-safety score: an editorial judgment of how comfortably a solo traveler can navigate the city, grounded in cited authoritative sources (safety reporting, transit reliability, late-night norms), with at least one recorded source and a written basis per score. Cities are ranked by this score alone.
What the score is not
Safety is personal and situational; the score is a disclosed editorial judgment applied uniformly, not a crime statistic. Read it as relative guidance across the cities we cover, alongside each city's own safety guide.
The universe
Each edition ranks every city TTDI covered at the moment the edition was cut — the cities whose pages we publish and stand behind. The universe size is stated on every edition; an edition is never cut over fewer than 12 qualifying cities. As coverage grows, later editions rank more cities.
How ranks are assigned
Ranks are competition-style: cities with equal values share a rank, and the next distinct value resumes at its ordinal position (1, 2, 2, 4). We never separate tied cities alphabetically — a tie is reported as a tie.
Editions are frozen
Every edition is a frozen snapshot: once published, its ranking never changes, so a citation of this edition stays accurate. Updates ship as new editions at their own URLs; prior years remain available.