What-If Studio · Module 1 — Speed-Limit Corridor Delta

Relative scenario deltas under fixed, measured demand — exposure & kinetic-energy analysis, not a crash prediction. Statewide catalogue of corridors with ≥50% of length in posted 100/110 km/h zones — whole-corridor unit. crashstats.com.au family.

Corridor — search the statewide ≥100 km/h catalogue

Priority view — corridors ranked by collective risk (CR, modelled FSI/km/yr, descending)

#	Corridor	km	CR	FSI/yr

Top 200 shown — search box covers the full catalogue. CR is a per-km density: short corridors rank high; FSI/yr shows absolute burden.

Length (km)

AADT (veh/day)

Current limit (km/h)

Proposed limit (km/h)

Speed response — mean-speed change per 1 km/h of limit change: Conflict types present on corridor

Head-on possible (undivided) Side impacts (intersections) Pedestrians / cyclists present Run-off-road (trees/poles)

Demand fixedDelta-onlyNo OD inference Method: Nilsson power model with Elvik-refined exponents (fatal 4.6, serious 3.6, all-injury 2.4, range shown vs classical 4/3/2); kinetic energy ∝ v²; Safe System survivable impact speeds (head-on 70, side 50, ped/cyclist 30, fixed-object 40 km/h). Mean-speed response default 0.5 × limit change (field-observed range 0.25–1.0).

Fatal-outcome index

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Serious-injury index

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Kinetic energy / vehicle

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at mean operating speed

Travel time cost

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Honesty box. This tool moves exposure and energy, not proven crash counts: converting these deltas into expected-casualty claims requires an EB/CMF evaluation design (separate, gated). Demand is measured or banded AADT taken as given — this platform family does not infer traffic volumes from models (that lane was tested and retired). Speed-response and exponents are user-visible assumptions; drag the slider to stress-test the conclusion.

Catalogue provenance. Corridor unit is the crashimpact physical-LRS corridor, whole extent. A corridor is listed when ≥50% of its length lies in a posted 100/110 km/h zone (DTP speed zones, May 2026 vintage; length overlay computed in EPSG:7899 with zones buffered 30 m; corridors under 1 km, ramps and unnamed roads excluded); the scenario applies over the whole extent including any lower-speed parts. Corridors with a 50–55% high-speed share are marked borderline — inclusion is sensitive to geometry alignment. AADT is two-way, length-weighted over the whole corridor (vGOLD6 banded overlay v2); the divided/head-on flag is inferred from carriageway topology, not audited. This is a screening catalogue, not an authoritative speed-limit inventory. The unit is the physical corridor (connected same-name extent): a long named highway can appear as several physical corridors where connectivity breaks. CR = modelled FSI/km/yr (crash_risk_v2, all sections, whole-corridor length) per the DTP-NSP collective-risk convention — a screening density, not a treatment-effect estimate. Basemap and map library are runtime CDN dependencies.