SILO
SILO (Simple Integrated Land Use Orchestrator) is a microsimulation land use, demographic, relocation, employment and housing model (TUM, 2018).
More fully, it is a microsimulation model for representing the spatial development of households, population, employment, housing and land use over time (Ziemke, Nagel and Moeckel, 2016).
| Developed at | Technical University of Munich |
| Website | silo.zone |
| Type | Microsimulation land-use and demographic model |
What makes it a microsimulation
SILO simulates demographic events and the relocation decisions of individual households and persons, rather than applying only aggregate growth rates to zones.
The processes it can represent include:
| Process category | Events represented |
|---|---|
| Demographic | Births, deaths, household formation and dissolution, migration |
| Economic | Changes in employment |
| Housing supply | Construction, demolition |
| Location | Household relocation |
By linking demographic change, housing markets, employment and spatial development, SILO can be used to examine how land-use policies, housing supply, accessibility and socioeconomic conditions influence the evolution of an urban or regional system.
Why this matters for transport
Where people live and work is not fixed. A new development, a housing policy or a change in accessibility will move people around, and that changes travel demand before any transport intervention is considered.
SILO lets the demand side respond to those changes rather than treating the population distribution as a constant.
Required inputs
Base-year synthetic population
SILO requires a base-year synthetic population of households and persons with demographic, socioeconomic, housing and spatial attributes. Relevant variables include:
- Age
- Sex
- Household composition
- Income
- Employment status
- Workplace location
- Housing type
- Dwelling size
- Tenure
- Residential location
Spatial and land-use data
Additional inputs describe the places those people live in:
- Zones or parcels
- Existing housing stock
- Land-use categories
- Developable land
- Housing construction and demolition assumptions
- Employment locations
- Accessibility or travel-time information
Behavioural parameters
Parameters are required to represent population and land-use change, and to calibrate the behavioural processes:
- Demographic rates
- Migration assumptions
- Household-formation probabilities
- Employment-transition rates
- Housing preferences
- Relocation or location-choice parameters
Scenario inputs
Depending on the application, SILO may also use policy scenarios:
- Zoning restrictions
- Development capacities
- Housing costs
- Infrastructure investment
- Alternative land-use policies and regulations
How SILO advances the system
SILO advances the population and land-use system through a sequence of demographic, economic, housing and relocation events.
Individual life courses change. Persons and households may experience births, deaths, changes in employment, household formation or dissolution, and migration into or out of the study area.
Households consider moving. They evaluate housing alternatives and may relocate in response to housing availability, costs, dwelling characteristics, accessibility, neighbourhood conditions and household preferences.
Housing supply updates. The model changes the stock through construction, redevelopment and demolition.
Opportunities shift. Employment and land-use changes modify the spatial distribution of opportunities, which feeds back into where households want to be.
Generated outputs
SILO generates time-series representations of synthetic households and persons, with updated:
- Demographic and socioeconomic characteristics
- Residential locations
- Housing characteristics
- Employment status and workplace locations
It also produces spatial distributions of population, employment and housing.
Where the outputs go
These outputs can be used two ways:
| Use | Description |
|---|---|
| Land-use analysis | Aggregated to zones |
| Travel-demand generation | Passed to travel-demand models such as MITO to generate individual travel demand for subsequent MATSim simulation |
The second route is what supports an integrated SILO, MITO and MATSim modelling framework, where land use, travel demand and network simulation are linked end to end.