Zoning & Infrastructure Growth Simulator

Zoning Brush

Zone density Medium

Growth Dynamics

Growth rate r 0.045 / yr

Infrastructure reach 4 blocks

City Readout

Total population

Sim. years elapsed

0.0

Avg. capacity used

Zoned blocks

Road — grants infrastructure access

Residential — grows toward K

Commercial — grows toward K

Industrial — slower, higher K

How it works

Each zoned block's population P follows logistic growth toward a carrying capacity K set by its zoning density and road access:

dP/dt = r · P · (1 - P/K)
K = K_base(type, density) · infra(d)
infra(d) = max(0.15, 1 - d / reach)

where d is the block's distance (in grid cells) to the nearest road. A block far from any road is capped near 15% of its zoned capacity no matter how it's zoned — infrastructure, not zoning alone, is what unlocks density. Residential and commercial blocks share a baseline growth rate; industrial blocks grow at 0.6× that rate but tolerate a higher capacity ceiling once served.

Zoning brush — paint a block's land use; density (Low/Medium/High) sets its target K_base before infrastructure discount.
Road — the only source of infrastructure access; every block's growth ceiling is discounted by its distance to the nearest road within the reach radius.
Growth rate r — the logistic rate constant shared by residential/commercial blocks (industrial uses 0.6r).
Building height in the 3D view is proportional to a block's current population P; color encodes zone type.

This is the same coupling real planning departments reason about qualitatively: rezoning for higher density does nothing on its own if roads, transit and utilities aren't extended to match — capacity is jointly constrained by land-use policy and infrastructure investment.

Click or drag on the grid to zone a block.

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