Falstad Circuit Simulator
falstad.com
Build a circuit and watch the electrons move through it
Sandboxes & SimulatorsA minuteFree, no sign-up
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Sandboxes & Simulators
Find out why a jam appears when nothing is blocking
traffic-simulation.de
A minute · Best on desktop
Free, no sign-up · online since 2013
Ring roads, motorway merges, roadworks and junctions each get their own scenario, with sliders for inflow, politeness, time headway and driver aggression. Trucks and cars follow separate rules, and you can drop an obstacle into a lane while the whole thing is running.
The ring road demo shows a phantom jam forming out of nothing but one driver braking slightly too hard, which quietly explains most of your commute.
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Picked for a shared category and overlapping vibe, not for popularity.
falstad.com
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