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🗺️ 2D City Growth — Road-Weighted Urban CA

A road-network-driven urban cellular automaton in flat 2D. Development probability comes from real accessibility: distance to the nearest road plus distance to existing development. Tune road attraction to switch between compact and sprawling growth.

Transport & Urbanism2DModerate60 FPS📱 Mobile-adapted⇄ 3D version

🗺️ City Growth 2D — Road-Weighted Urban Cellular Automaton

A flat 2D cellular automaton where a real road network — a highway cross, a diagonal arterial, and a ring road — drives urban development. Growth probability comes from an accessibility field built from actual distance to the road network and to existing development, not from a simple neighbour count.

🔬 What It Demonstrates

Each empty cell's chance of developing is growthRate × (roadWeight × 1/(1+roadDistance) + devWeight × 1/(1+devDistance)), where both distances come from real multi-source breadth-first searches over the grid. High road attraction produces ribbon-like sprawl that leapfrogs along corridors; low road attraction produces compact, contiguous growth that hugs the existing built-up edge.

🎮 How to Use

Drag Road attraction toward 100% and watch development jump out along the yellow road lines, far from the core. Drag it toward 0% and growth instead fills in a tight, concentric city. Growth rate and Densify scale the underlying probabilities as usual.

💡 Did You Know?

This mirrors real "accessibility-based" urban growth models used in planning practice, where transport infrastructure — not just proximity to other buildings — is one of the strongest predictors of where new development appears.

⚙ Under the hood

A flat 2D urban cellular automaton driven by a real road network — highway cross, diagonal arterial and ring road — rather than raw neighbour counts. Each empty cell's development probability comes from an accessibility field combining actual BFS-computed distance to the nearest road and to existing development, so a road-attraction slider genuinely switches the outcome between ribbon-like sprawl along corridors and compact, contiguous growth around the core.

Cellular AutomatonUrban SprawlRoad NetworkAccessibility ModelLand Use ChangeCompact vs SprawlUrban Planning

2D · HTML5 Canvas 2D · 60 FPS target · runs fully client-side, no install