A crashstats.com.au Product · Road-Safety Intelligence

SignalWatch
Screen the network monthly. Don't wait years for the crash history.

A fatal & serious injury (FSI) risk-screening product for signalised intersections — fusing SCATS per-leg traffic volumes with connected vehicle near-miss data to rank every covered site by exposure-controlled residual risk, refreshed monthly. Live for Melbourne metro today; built to scale statewide.

Monthly
screening-rank refresh — vs the multi-year lag of crash-history lists
Every leg
SCATS detectors on all approaches of every signalised intersection
2,141
metro intersections scored in the live demonstrator, today
View the live v0 demonstrator → 2,141 covered metro intersections scored · live demonstration

The problem: FSI is rare, so reactive lists are slow

Serious casualty crashes at any single intersection are statistically rare events. Blackspot programmes must therefore wait years for crash history to accumulate before a site qualifies for treatment — by which time the harm has already occurred. Volume and crash history alone predict essentially none of the FSI variation at fine scale. Victoria already collects, every day, two data assets that together change this.

Exposure · SCATS

Per-leg traffic volumes, network-wide

SCATS loop detectors sit on every leg of every signalised intersection in Victoria, logging 15-minute counts published as daily volume files. That yields per-approach AADT — an exposure denominator at intersection-leg resolution that routine crash-history screening rarely has access to.

Surrogate risk · Connected vehicles

Near-miss telematics

Connected vehicle telematics captures harsh-event near-misses across the network — a leading indicator observed thousands of times more often than serious crashes. Raw density is largely a volume echo; the signal lives in the residual above exposure expectation.

Output

Monthly ranked screening list

Each month: every covered signalised intersection scored by its near-miss residual — what remains after SCATS exposure expectation is subtracted, never raw density — ranked and mapped as a prioritisation layer for signal-operation tweaks, low-cost treatments and blackspot funding.

How it works

SCATS daily volumes 15-min counts, every leg Connected vehicle feed harsh-event telematics Per-leg AADT exposure baseline Near-miss intensity per intersection, coverage-masked Exposure-controlled residual risk Monthly ranked screening list

The evidence so far

The core question — does near-miss data add FSI signal beyond traffic volume? — has been tested and published in the Near-Miss × Crash Divergence study (Melbourne metro, 2023–25, exposure-hardened with real AADT).

FSI deviance explained: 0.00 → 0.054

In a Poisson model with a real AADT exposure offset, exposure alone explains essentially none of the FSI variation. Adding near-miss features lifts it to 0.054 — a modest, grid-level (1 km) effect, but it is signal where volume alone predicts nothing. Translating it to per-intersection decisions is the pilot's validation task.

Near-miss intensity → FSI share: ρ = 0.207 (p = 0.015)

The severity link strengthens under exposure control (from ρ = 0.181 raw) — harder braking intensity correlates with a higher share of severe outcomes, independent of volume.

Raw density ≈ volume echo (partial r = 0.11)

Honest finding: raw near-miss density adds little once traffic volume is controlled. This is exactly why SignalWatch is built on the residual — and why SCATS per-leg exposure is the non-negotiable backbone of the design.

Full method, interactive maps and all findings: nearmiss.crashstats.com.au

Scope & assumptions

  • Screening, not prediction. The evidence supports relative risk ranking, not site-level crash forecasts. No causal claims are made.
  • Metro telematics coverage first. 38% of metro crash cells had zero near-miss coverage in the study period; v1 scores only well-covered metro signalised intersections, with an explicit coverage mask.
  • Grid-level evidence, intersection-level engineering. The published study operates on a 1 km grid; translating to per-intersection scores is the pilot's build task, not a solved input.
  • Monthly, not real-time. SCATS volume files and telematics processing set a monthly refresh cadence — still an order of magnitude faster than crash-history lists.
  • Turn-vs-through attribution at signals is an open item, treated as a gated dependency with a planned micro-simulation fix.
  • Fleet bias is unquantified. Telematics vehicles are not a random sample; penetration bias by area is measured and reported before any operational use.

Validation pathway: operational decisions follow prospective validation in Phase 1 — lift measured against a volume + crash-history baseline under spatially-blocked cross-validation.

Roadmap — every phase behind a gate

PHASE 1 · 6–12 MONTHS

Metro validation pilot

Build the monthly pipeline for covered metro signalised intersections. Deliverables: monthly ranked screening lists, a prospective validation report against held-out future FSI, and a fleet-penetration bias study.

Success metric: demonstrated lift in top-decile capture of next-period FSI vs volume + crash-history baseline.
PHASE 2

Intersection-level hardening

Per-leg exposure refinement, turn-movement attribution via micro-simulation, coverage expansion, integration with treatment catalogues for signal-operation and low-cost countermeasures.

Gate: attribution validated against counted turning movements.
PHASE 3

Statewide operation

Extend to all Victorian signalised intersections as telematics coverage allows; embed in blackspot and safe-system investment cycles with measured prevented-FSI reporting.

Gate: Phases 1–2 cleared; coverage sufficient outside metro.

Why this matters to TAC

TAC funds the infrastructure and pays the claims. Reactive lists spend the treatment dollar only after casualties accumulate. SignalWatch ranks the covered signalised network by exposure-controlled residual risk every month, so investment can be screened toward the sites carrying elevated surrogate risk — with every operational use conditional on prospective validation first.

The offer: a 6–12 month metro pilot engagement — monthly ranked screening lists from month one, a prospective FSI-lift evaluation against a volume + crash-history baseline, and a fleet-coverage study — with success metrics co-designed with TAC’s technical team. The pipeline is already running; the pilot turns it into a decision tool TAC can defend.