PPolySim OS
For K-12 Students · Traffic Flow Planner

Traffic Flow Planner for a GDP forecast

Built for k-12 students learning it in middle or high school. Watch the idea come alive with plain-language steps and everyday examples — perfect for projects and homework. Simulate a GDP forecast live below — adjust the inputs and watch it respond, right in your browser.

Traffic Flow StudioLive

Controls

A ring road of cars. Random braking alone creates phantom traffic jams that travel backward — no accident needed.

Presets

▶ Run in Python

Data Inspector

Cells160
Avg speed0.00
Density0.30
ModelNagel–Schreckenberg

Governing equation

Reading this result: Above critical density: stop-and-go waves dominate. Average speed drops sharply — this is the falling branch of the fundamental diagram.

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

2

Shortest Path

open full solver →
Shortest Path (Dijkstra)Live

Controls

Dijkstra's algorithm finds the shortest path from a source (A, blue) to every other node in a weighted graph, always expanding the closest unvisited node next. The number inside each node is its shortest distance from A; the green edges trace the optimal route to your chosen destination. It powers GPS routing, network protocols, and logistics. Click any node to re-target.

Size a graph for the exportable Python solver below — the diagram stays a fixed six-node example.

Presets

▶ Run in Python

Data Inspector

SourceA
DestinationF
Shortest distance11
Graph size6 nodes
Est. edges9 (60%)

Governing equation

Reading this result: Dijkstra grows a set of finalized nodes, each step expanding the nearest unvisited one and relaxing its outgoing edges. Because all weights are non-negative, the first time a node is finalized its distance is already optimal. This configuration describes 6 nodes and about 9 weighted edges (density 60%).

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

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More with Traffic Flow Planner

Frequently asked questions

Is this good for k-12 students?
Yes — this version of "Traffic Flow Planner for a GDP forecast" is framed for k-12 students learning it in middle or high school. Watch the idea come alive with plain-language steps and everyday examples — perfect for projects and homework.
Do I need to install anything?
No. It runs in any modern browser, free, with no account required.