nearmiss — where the danger actually is
Rates are shown with 95% confidence intervals. Segments without a trustworthy exposure denominator are shown as uncertain and are never ranked as if certain.
Summarizing…
Two maps, the same reports
The same near-miss reports, mapped two ways on a real street map. On the left, the raw report count — what most safety maps show: the busiest street looks the most dangerous. On the right, the rate per 1000 units of exposure — which is what actually reflects danger. Watch the busiest street recede and the real hotspot emerge. Nothing is conveyed by color alone: line thickness scales with the value, and significant hotspots are dashed and labeled. Everything here is in the data table, which the maps supplement.
Summarizing hotspots…
Ranked segments
Sort the table with the column buttons. Significance and confidence are stated in words, not by color.
| 95% CI | Hazards | Confidence | Exposure tier | Quality flags | ||||
|---|---|---|---|---|---|---|---|---|
| Loading published data… | ||||||||
How to read this
- Rate /1000 — reports per 1000 units of exposure, not a raw count.
- 95% CI — the plausible range. A wide range means uncertainty.
- Confidence — “uncertain” marks small samples; “exposure unknown” marks segments with no denominator (never ranked as if certain).
- Hotspot (Gi*) — “★ Significant” marks a statistically significant cluster (Getis-Ord Gi*, z > 1.96): hot beyond what exposure and chance explain.
Reporting bias
Who the data over- and under-reports
Over-represented in reports
Under-represented
Questions people ask
Why isn’t my busy street the most dangerous one?
Because volume is not danger. A busy street collects the most reports simply because the most people use it. We divide reports by exposure (how much cycling each street carries), so the map shows the rate per rider, not the raw count. A high-traffic street can have many reports and still be safer per trip than a quiet one with a few.
Is a near-miss the same as a crash?
No. These are self-reported near-misses and hazards, which by definition usually leave no police report. They are an early-warning signal, not verified injuries or collision statistics, and we never present them as such.
What does “exposure unknown” mean?
It means we have no trustworthy count of how many people cycle that street, so we will not invent a denominator. Those segments are shown as uncertain and are never ranked as if we were sure. A rate without a denominator is not published.
How do I know which streets are really hotspots?
A street is marked “★ Significant” only when a statistical test (Getis-Ord Gi*, with a false-discovery-rate correction) says it is hotter than exposure and chance alone would explain. Everything else carries a confidence interval so you can see how sure — or unsure — the number is.