Pick a system and push on it.
Each simulation is a working model. Start from one of its questions, or just move a slider.
Traffic World
Traffic Ring
Buses circle a 25 km route, one every eight minutes. Let a stop get busy, or a light hold one bus, and watch an even timetable turn into long gaps and bunches of buses arriving together.
Traffic World
Phantom Jam
Dozens of cars share a closed road. One brakes hard, then drives on, and the jam it started stays behind, moving backwards, with nothing in the way.
Traffic World
Green Light
A four-way junction with left-turn arrows and amber lights. When a light turns green, how quickly the waiting queue sets off decides how many cars get through.
Nature World
Predators & Prey
Foxes hunt hares across a meadow. Every animal is an individual that eats, breeds, starves or gets caught. Change the rules and watch the populations boom, crash or disappear.