---
title: "Aggregate traffic-crash context by radius, severity, and mode"
method: POST
path: "/api/locus_traffic_crash_context"
tags: ["traffic", "crashes", "transportation", "aggregate", "safety", "read-only", "free", "free"]
---

# Aggregate traffic-crash context by radius, severity, and mode

`POST /api/locus_traffic_crash_context`

## Request

- Base URL: `https://api.locus.report`
- URL: `https://api.locus.report/api/locus_traffic_crash_context`
- Auth: none required

Suppressed police-reported crash counts at 200-1,000m. Coverage: Chicago all-reported; Virginia reportable-threshold; North Carolina partial subsets (K+A and nonmotorist); Pikes Peak region reportable-threshold; nationwide FARS fatal-only companion. Per-source severity and lag; no raw rows or exact points.
Use this when you can call Locus free tools (REST tools/call or MCP).
Use locus-traffic-crash-context instead when your client can only call paid x402 routes; it returns the same records. Direct flat-body route for this one free resource; no API key, payment, or catalog wrapper. Return only the cited bounded evidence described here; this route never produces a paid brief or full report.

## Request body

- object
  - `address` string: US street address. Localized coverage is derived from the crash-source registry: Chicago all-reported; Virginia reportable-threshold; North Carolina partial subsets (K+A and nonmotorist); Pikes Peak region reportable-threshold; nationwide FARS fatal-only companion. Provide this or latitude+longitude.
  - `latitude` number: Decimal latitude; provide with longitude. The response never returns the exact query point.
  - `longitude` number: Decimal longitude; provide with latitude. The response never returns the exact query point.
  - `radiiMeters` integer[]: One to three bounded radii in meters; each must be 200-1,000. Defaults to 200, 500, and 1,000.
  - `lookbackYears` integer: Recent calendar lookback in years; defaults to 3 and is capped at 10. A source's actual available years still control.

## Response `200`

Free cited evidence response.

- object

## Other responses

- `400`: Invalid request body.
- `429`: Rate limited.

---

[API](https://skmtc.dev/locus/apis/locus-api.md) · [All operations](https://skmtc.dev/locus/apis/locus-api/llms.txt) · [OpenAPI document](https://skmtc.dev/locus/apis/locus-api/revisions/ba7786b74adb?raw)