Scenario Planning Model

Features

SPM provides a powerful and dynamic scenario creation, modeling, and data organization planning tool to facilitate informed and collaborative planning by providing a comprehensive view of potential futures. SPM’s suite of tools and analytic engines enable the creation and organization of local and regional data, plans, and policies; facilitate scenario creation and editing; and estimate a wide range of potential benefits resulting from alternative transportation and land use strategies.

Data Development and Organization

Scenario-based planning with SPM starts with a detailed baseline assessment of the existing conditions. SPM streamlines the development of this highly detailed “canvas” of data by normalizing data of varying quality, type and scale from a wide range of sources, including land cover, environmental data, demographic characteristics, roadways, and transit, which provide context for scenario painting and editing as well as subsequent analysis.

Scenario Development

SPM scenarios are created by analyzing or translating key characteristics of future year conditions, such as density, mix of uses, and street connectivity into SPM’s common language of Place Types and Building Types. Place Types represent a full range of potential development types and patterns from across the SCAG region. Each Place Type includes a mix of different building types and represents a unique set of assumptions that facilitate scenario modeling and testing at a variety of scales. This allows SCAG to integrate local plans together into a common regional fabric of land use and transportation plan and to perform consistent analysis on individual plans or combinations thereof.

Scenario Analysis

SPM produces a wide range of inter-related metrics that allow for robust and meaningful comparisons of alternative land use and transportation scenarios. These scenarios run through SPM’s analysis modules briefly described below to measure their performance for mobility, air quality, public health, fiscal impacts, resource consumptions, and others.

Building Energy Module 

The Energy module computes residential and commercial building energy use, and their related costs and greenhouse gas emissions. Within the module, building characteristics and climate zone determine baseline energy use factors. Reductions are then applied to the resulting baseline estimates to reflect the implementation of building efficiency and conservation policies into the future. 

Building Water Module

The Water module calculates indoor and outdoor residential and commercial water use and their related costs and greenhouse gas emissions. Indoor and outdoor water use is calculated according to baseline rates, determined by building or employment characteristics and climate zone and then adjusted to account for the application of efficiency and conservation policies into the future. 

Public Health Module

The Public Health module measures the impact of land use patterns and urban form on a range of health-related metrics within two broad categories: those that are derived from factors influenced by changes in urban form, including physical activity-related weight and disease incidences; and those that are derived from changes in travel behavior as expressed by VMT, including pollution-related respiratory impacts. 

Accessibility Module 

The Accessibility module evaluates the level of opportunities accessible by active modes of travel, including walking, biking, and transit. Based on an integrated active transportation network, accessibility can be measured for each mode as the number of opportunities reachable within a specified amount of time or travel times to the nearest amenities. 

Transportation Module

The Transportation module estimates trip generation by different trip purposes and models in response to changes in land use pattern or policy options. By referencing forecasts obtained from SCAG’s Activity Based Model (ABM) that simulates daily activities and travel patterns of all individuals in the region, the SPM transportation module represents the ABM’s detailed insight into complex relationship while allowing quick calculation of trips and vehicle miles traveled. 

Land Conservation Module

The Land Conservation module measures the impacts of land use and land cover scenarios on conservation opportunities and ecosystems. Built upon a detailed depiction of existing conditions, the impact of land use changes are measured on the themes of carbon, water, agriculture, and habitat. 

Land Consumption Module

The Land Consumption module assesses how land use is developed in a future scenario. In the context of the model, “land consumption” refers to the measurement of land area needed to accommodate new growth on ”greenfield” or previously undeveloped land. 

Fiscal Impact Module

The Fiscal Impact module evaluates the implications of new residential development on local expenditures by accounting for the capital costs of new and upgraded infrastructure and local operations and maintenance costs to serve new and upgraded infrastructure.