Railway headway & capacity simulation

See how your railway behaves — before a single train runs.

Best Headway models rolling stock, routes, signalling and interlocking with real ATO physics, entirely in your browser. No install, no server — just answers.

TIME–DISTANCE, ACTUAL RUN 4 trains · sim_log
05:59 06:12 28.1km 24.9km ≈2 min headway
The pipeline

Seven stages, one contract

Each module reads a clean input and writes a clean output — chain the full pipeline, or run any stage on its own.

01
Track Layout
Tracks, signals, gradients & crossovers
02
Rolling Stock
Length, speed, accel & braking rates
03
Route Info
Signal-to-signal blocks, gradient, speed
04
Scenario Builder
Departures, stops & dwell times
05
Simulation Engine
Tick-based physics & ATO logic
06
Interlocking
Route conflict & occupancy checks
07
Results
Time–distance & speed–distance diagrams
Inside the engine

Every tick, one decision

Module 5 drives each train through a 3-zone ATO strategy — the same brake/cruise/accelerate logic a real automatic train operation system uses.

Zone 1

Brake

Full service brake applied — the train must slow now to reach its target speed at the target point.

braking_dist ≥ distance_to_target
Zone 2

Cruise

No traction, no braking. The train holds speed at or just under the current limit.

speed ≥ speed_limit
Zone 3

Accelerate

Full service acceleration — below the limit, with no braking required yet.

speed < speed_limit
Capabilities

Built for real headway analysis

Not a toy model — a physics-based engine, editable data at every stage, and diagrams built for the questions operators actually ask.

Δv

Real kinematics

SUVAT displacement, speed and chainage updates every tick — not linear approximations.

t

Discrete-time engine

A configurable tick interval drives every train's state machine from departure to terminus.

Time–distance diagrams

See headway, conflicts and spacing across the whole timetable at a glance.

Interlocking-aware

Route and occupancy checks surface conflicts before they reach the real network.

Editable at every step

Routes, sections and scenarios are inline-editable tables with live validation.

Zero install

Pure client-side. No server, no build step, no account — open it and run.

Who it's for

Built alongside the people who plan railways

Operators

Transit authorities

Pressure-test headway and capacity assumptions on your own network before committing to a timetable.

Consultancies

Engineering firms

Run fast, repeatable capacity and signalling studies across client engagements.

Vendors

Rolling stock & signalling

Demonstrate the headway performance of your systems with data, not slideware.

Academia

Research & teaching

A transparent, inspectable physics model for coursework and rail operations research.

Curious what it looks like on your network?

Send a note and we'll walk you through a run on a scenario close to yours.

Contact us →