What it is
Simulation represents a system with rules or mathematical relationships so planners can explore how it may behave under selected conditions. City simulations include traffic, flood, energy, pedestrian, and land-use models. Results depend on assumptions, calibration data, and scope; a scenario is not a forecast unless its probability and validation are established.
Explore the City Digital Twins directory → to browse city models and documented connected twins, with separate implementation, lifecycle, and access classifications.

How it works
- 01Define the decision, boundary, time horizon, and model purpose.
- 02Document inputs, assumptions, and calibration against observed conditions.
- 03Run alternative scenarios and sensitivity tests rather than one preferred case.
- 04Compare modeled outcomes with real measurements and explain uncertainty to decision-makers.
- 01
Define the decision, boundary, time horizon, and model purpose.
- 02
Document inputs, assumptions, and calibration against observed conditions.
- 03
Run alternative scenarios and sensitivity tests rather than one preferred case.
- 04
Compare modeled outcomes with real measurements and explain uncertainty to decision-makers.
Why it matters
Cities need to assess interventions before committing resources or changing daily travel and service patterns. Scenario models can make trade-offs visible, but participation and local evidence are needed to test whether the model represents lived conditions.
Typical Smart City applications
- Transit or street redesign
- Flood and heat adaptation
- District energy planning
- Emergency route and capacity analysis
Example data inputs
Strengths
- Allows systematic comparison of alternatives
- Can test rare or disruptive conditions
- Makes dependencies and assumptions explicit
Limitations and risks
- Model outputs can appear more certain than underlying assumptions justify.
- Simplified behavior may not represent residents or operators.
- Calibration to past conditions does not establish future performance.
Illustrative workflow
Applied city example
A transport department models a bus-priority lane under multiple traffic and ridership scenarios. It publishes assumptions, compares the model with recent corridor observations, and pilots the change with a monitoring plan before deciding on permanent construction.
Related methods
- Urban digital twins
- Geospatial analytics
- Regression algorithms
- Optimization algorithms
Frequently asked questions
Is a simulation a prediction?
Not by itself. It explores specified assumptions; prediction requires validated probabilities or forecasting performance.
How can the public review model assumptions?
Publish understandable documentation, scenario inputs, limitations, and ways to compare results with local experience.
Should a simulation determine policy?
It should inform decisions alongside public goals, field evidence, legal duties, and community input.