Transcript Slide 1
Stephen Lawe RSG Michael Doherty URS MAY 2013
HELIOS:
Household Employment and Land Impact Outcomes Simulator
FLORIDA STATEWIDE IMPLEMENTATION
Development & Application
Presentation Outline 1. Model Introduction
Model Goals & Process Model History
2. Model Development
Data Used Estimation and its challenges Model structure
3.
Model Evaluation
Southwest Example
4.
Model Use
Model Interface Projects where HELIOS was used
Goals during development HELIOS
Consistent Land Use Forecast Initially used to refine the Turnpike ME process Integrate into the statewide and MPO models Support multiple geographic levels (parcels, different TAZ boundaries, etc.)
Sensitive to accessibility. Able to integrate into any transportation model.
Modest Runtimes:
The model runs the entire state of Florida in less than 5 minutes for a specified time period Analysis of policy measures other than changes in accessibility run in less than 2 minutes
Model History
Implemented for Florida’s Turnpike at the Statewide Level.
2005
Model applied to
Southwest Florida Investment Grade Project
. Land use forecasts were used in Florida’s Turnpike Planning out to 2045.
Model applied to
Central Florida Investment Grade Project
. Forecasts used to 2060 Implemented for Florida DOT at the Statewide Level.
2006 2007 2008 2009
Setting the Stage Peer Reviewed
2010 The Florida MPO Land Use Model Task Force reviewed a broad range of tools and has suggested that HELIOS be made available across the state.
Application History
14 Managed Lane Studies Wekiva Parkway Suncoast 2 Suncoast 3 [ Tampa to Jacksonville Corridor ] I295 / I95 Managed Lanes Turnpike System Forecasts [ Traffic Trends Process ]
HELIOS Process 1.
Determine control totals to be allocated 2.
Apply Developments of Regional Impact (DRI) growth to known TAZs 3.
A.
B.
Allocate remaining:
Determine land availability including converting some agriculture land Apply a probability model to distribute remaining growth to vacant lands and underutilized developed areas 1 BEBR Forecast (Control Total) 3 Allocate remaining A GIS Process
vacant residential, non residential, and converted agricultural land
2 DRIs in County B Probability Model Applied with iterative scaling
Model Development
Data Inputs for Model
Estimation
Parcel-level land use Urban Planning Boundaries (urban growth constraints) Geoprocessing with GIS (proximities) Base Year Socioeconomic Data
Model Implementation
Generalized land use Developments of Regional Impact
DRIs
Data Cleaning – InfoUSA Employment
Land Use Data – Development History (parcel level)
Land Use Data – Lumpy by Year 1200 1000 800 600 400 200 0
Vacant
1985
Build Year
1990 1995 849 1,132 2000 2005
Land Use Data – Spatial Variability (parcel variability)
Land Use Data – Urban Growth Boundaries (legal constraints)
Model Structure – Two Stage Logit/Linear
1. Logit Model Estimates: P
i
= Probability of Development P
i
= Pr(Y
i
= 1 | X
i
) =
e
ἀ + β
1
x 1
1 + e
+ β
2
x 2 ἀ + β
1
x 1 +…+ β
k
x k + β
2
x 2 +…+ β
k
x k
2. Linear Model Estimates: Y = Intensity of Development Y(g) = β
1 x 1 + β 2 x 2 +…+ β k x k Where (g) is a log link function
Resulting outcomes scaled to control totals
Model Structure – Parameters of Model
Variable
Accessibility Distance from Coast Distance from Arterials & Interchanges Density of Current Use Undeveloped Area Mix of Land-Uses Urban Growth Boundary
Res. & Non-Res. Development History Source
Travel Model GIS GIS/Travel Model Parcel Parcel Parcel GIS layer
Parcel Effect on Development
Positive Negative Negative Non-Linear, generally positive Non-Linear, generally positive Homogeneity is positive Less development outside UGB
(dependent variable)
Model Evaluation in Lee-Collier Planning Region
Model Structure – Calibration Results (Residential Growth 1980 - 2005) Observed Growth Modeled Growth Pearson’s Correlation
TAZ= .58
ZIP = .81
Model Sensitivity Test - Accessibility
Significant bridge capacity added during 1990s
Large subsequent observed increase in development in Cape Coral
Modeled removal of new bridge capacity
25% decrease in HH growth in Cape Coral 40% decrease in Employment growth in Cape Coral
Legend % Difference HH
-0.53 - -0.40
-0.39 - -0.30
-0.29 - -0.25
-0.24 - -0.20
-0.19 - -0.15
-0.14 - -0.10
-0.09 - -0.05
-0.04 - 0.00
0.01 - 0.11
Model Use
Model Structure – Land Conversion Algorithm
Agricultural Land
According to US Census of Agriculture, FL farmland declined from 10.4 M acres in 2002 to 9.2 M acres in 2007
We assume this continues; each modeling period, a fraction of agricultural land becomes available for development
HELIOS - Final Observations
Inconsistent Inputs to HELIOS
It is possible to give the model an “inconsistent set of inputs”. An example would be growth control totals that exceed the available land HELIOS warns the user and then “softens” the constraint assumptions to allow full allocation.
This provides “what if” testing but also requires user consideration
Recession Impacts: comparison of 2006 and 2012
New Growth assumptions Revised Occupancy assumptions Revised Agricultural land conversion assumption
Policy Shifts
Shifting DRI Designation
Model Interface
Windows Executable
Text file inputs and outputs
Ability to turn on/off key features (accessibility and distance calculations)