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Utilizing Connected Travel Demand and Land Use Models in the Sacramento Region. Gordon R. Garry Sacramento Area Council of Governments April 30, 2010. Why improve SACOG models? . Models are tools to apply research in the most effective and comprehensive manner to address policy issues
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Utilizing Connected Travel Demand and Land Use Models in the Sacramento Region Gordon R. Garry Sacramento Area Council of Governments April 30, 2010
Why improve SACOG models? • Models are tools to apply research in the most effective and comprehensive manner to address policy issues • Research points to interrelated causes and consequences • Policy issues are often, and more frequently, interrelated
MEPLAN - LandEconomics to PECAS model I-PLACE3S - Land Use/Transportation Impacts SACSIM activity-based travel model Develop Better Information and Tools for Decision Making
PECAS and I-PLACE3S • Differences • Economic forecast vs. vision development • Path dependent vs. horizon year • Common elements • Parcel data • Development policy tools • Development costs and rents • Partial overlap • Employment types, residential definitions
Conclusions on land use models • Policy drives data and models • Incremental improvement = continuity • Model development is “pushed” by research advancements and “pulled” by policy needs • Integrated cross-discipline planning and decision-making can be improved with good analysis
Overview of Regional Travel Model (SACSIM) Performance characteristics A regional analysis example A land use project analysis example
Edit roadway links or roadway projects Edit transit routes Regional Transportation Plan Public Workshops
Roseville Fairgrounds Neighborhood Study Area Land Use Scenario 700 more employees 400 more dwelling units - 7 % VMT 74 Acres Changes from base case:
Two cities used I-PLACE3S to develop General Plan land use scenarios Local Land Use Plan Updates
User-Defined, includes: Inventoried allowed land uses Land uses that might not yet exist in codes (e.g. mixed use) “Place Types” are the Building Blocks
New Modules Developed Through King County WA Study Public health (outcomes: physical activity, BMI, walk and bike trips) Climate change and air quality (outcomes: CO2, NOx, HC, and CO; vehicle trips and VMT)
Climate Change Module (Household Inputs) • Household demographics • Working adults • Non-working adults • Children • Household Income • Access to transit • Area intersection density • Household area density • Area mix of land uses
Demographics Number of adults in household Employment status Number of children in household Ratio of adults to cars Household income Access to transit Intersection density Area housing density Area land use mix Park availability Area retail and fast food establishments Physical Activity and BMI Module (Person Inputs)
P roduction E xchange C onsumption A llocation S ystem
PECAS Framework Components • Economic Interactions (Activity Allocation): • Production to exchange to consumption location chains • determined for all goods, services and labor • Equilibrium markets for all commodities, with prices & clearing • Consumer surplus and producer surplus considered • Space Development (Land Use): • Changes in space year-to-year based on allowable zoning and prices from Activity Allocation • Links to: • Travel model (trip-based or tour-based) • Non-spatial economic model
Benefits • Apply economic analysis to spatial/land use issues • Simulate developer decisions in addition to government policies • Land use impacts for travel and emissions • Peak spreading of congestion • Pricing policy analysis • Improved impact assessment
Model comparison – Unit of Analysis • SACMET = TAZ and Trip • TAZ is a geographic area with number of people, jobs, etc. • Trips are “disembodied” and treated as a “gravitational” event • SACSIM = Persons and Tours • Population represents variety of people in a “real” way • Travel is an outgrowth of activities—a way of stringing activities together
Vehicle miles traveled as primary indicator Defining area types by average VMT per household Land use characteristics of VMT-defined areas Drilling down to specifics in prototype areas Forecasting results A Practical, Regional Planning Application
2005 VMT Per Household • 2005 reg. average VMT/HH = +/-50 miles • Dark green = Group 1--Very Low VMT (< 25 miles) • Light green = Group 2--Low VMT (25 – 45 miles) • Yellow = Group 3--Average(45-55 miles) • Orange = Group 4--High (55-75 miles) • Red = Group 5--Very High (75+ miles)
Density in Prototype Areas • Density = Jobs + housing per acre at place of residence • Higher density = lower VMT
Transit Proximity in Prototype Areas • Proximity = % of households within ¼ mile of nearest transit • Higher proximity = lower VMT
Mix of Use (Diversity) in Prototype Areas • Mix Index = 0 (homogeneous development) to 100 (balanced mix) • More balanced mix = lower VMT
Bike/Walk Mode Share in Prototype Areas • Regional Average = 7.5 % • Higher share in lower VMT areas
Transit Mode Share in Prototype Areas • Regional Average = 1.2 % • Higher share in lower VMT areas
The Project’s Internal Capture Vehicle Miles vs. External Areas