utilizing connected travel demand and land use models in the sacramento region gordon r. garry...
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Utilizing Connected Travel Demand and Land Use Models in
the Sacramento Region
Gordon R. GarrySacramento 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 - Land Economics to PECAS model
SACSIM activity-based travel model
I-PLACE3S - Land Use/Transportation Impacts
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
I-PLACE3S UsesRegional to Neighborhood-level applications
Regional Blueprint Land Use Scenarios
Regional Transportation Plan Public Workshops
• Edit roadway links or roadway projects
• Edit transit routes
Neighborhood Study Area Land Use Scenario
Roseville Fairgrounds
Changes from base case:
700 more employees
400 more dwelling units
- 7 % VMT
74 Acres
Local Land Use Plan Updates
• Two cities used I-PLACE3S to develop General Plan land use scenarios
“Place Types” are the Building Blocks
User-Defined, includes:
• Inventoried allowed land uses
• Land uses that might not yet exist in codes (e.g. mixed use)
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
Physical Activity and BMI Module (Person Inputs)
• 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
Demographic Variables
Density & Accessibility Measures
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
Typical Household’s Travel
Sample home
Central City
Shopping Center
Office
Trip 11
Trip 1,2,3
Trip 4
Trip 7
Trip 8,9,10School
Trip 12
Trip 13
Soccer field Trip 14,15
Trip 16,17
Office
Trip 5
Trip 6
A Practical, Regional Planning Application
• 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
2005 VMT Per Household
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
28
13
64 3
0
5
10
15
20
25
30
1 Very Low 2 Low 3 Average 4 High 5 Very High
VMT Grouping
Transit Proximity in Prototype Areas
• Proximity = % of households within ¼ mile of nearest transit
• Higher proximity = lower VMT
100%
91%
74%
22%
13%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
1 Very Low 2 Low 3 Average 4 High 5 Very High
VMT Grouping
Mix of Use (Diversity) in Prototype Areas
• Mix Index = 0 (homogeneous development) to 100 (balanced mix)
• More balanced mix = lower VMT
66
56
44
23
7
0
10
20
30
40
50
60
70
80
90
100
1 Very Low 2 Low 3 Average 4 High 5 Very High
VMT Grouping
Bike/Walk Mode Share in Prototype Areas
• Regional Average = 7.5 %• Higher share in lower VMT areas
37.4%
19.4%
7.7%5.5%
2.3%
0%
5%
10%
15%
20%
25%
30%
35%
40%
1 Very Low 2 Low 3 Average 4 High 5 Very High
VMT Groupings
Transit Mode Share in Prototype Areas
• Regional Average = 1.2 %• Higher share in lower VMT areas
7.4%
2.8%
1.3%
0.3% 0.1%
0%
1%
2%
3%
4%
5%
6%
7%
8%
1 Very Low 2 Low 3 Average 4 High 5 Very High
VMT Groupings
Curtis Park Village:A Development Project Example
Three Development Options
Project Housing and Employment Information
Total Housing
Units MF Units
SF Unit
s Comm.
Sq. Ft.Scenario
Developer Option B Plan 594 416 178 170,000
Developer August 2009 Plan 631 337 294 249,000
SCNA Plan 690 446 244 153,500
Project Area Travel Metrics
Year 2035 Weekday Travel Indicators for Curtis Park
Village
Develo
per Option
B
Develo
per Aug2009 Plan
SCNA Plan
Project Area Only
Vehicle Miles Traveled 12,830 17,198 15,343
VMT Per Person+Job 6.7 7.3 7.4
Transit Trips 156 177 202
Transit Mode Share 3.8% 3.5% 4.3%
Bike+Walk Trips 474 591 560
Bike+Walk Mode Share 11.7% 11.7% 11.9%Source: Sacramento Area Council of Governments, October 2009.
Project + Neighborhood Travel Metrics
Year 2035 Weekday Travel Indicators for Curtis Park
Village and Neighborhood Area
Developer
Option B
Developer
Aug2009 Plan
SCNA Plan
Expanded Project Area
Vehicle Miles Traveled 571,499 575,327 571,534
VMT Per Person+Job 16.3 16.2 16.2
Transit Trips 9,909 10,441 9,998
Transit Mode Share 6.3% 6.6% 6.4%
Bike+Walk Trips 13,930 14,135 14,110
Bike+Walk Mode Share 8.9% 9.0% 9.0%Source: Sacramento Area Council of Governments, October 2009.
The Project’s Internal Capture Vehicle Miles vs. External Areas
Year 2035 Weekday VMT To, From, and Within Expanded Project Area
Developer Option B
Developer Aug2009 Plan
SCNA Plan
VMT within Exp.Proj.Area 11,887 12,077 11,960
Diff from Opt.B Na +190 +72
VMT between Exp.Proj.Area and External Areas 559,612 563,250 559,574
Diff from Opt.B na +3,639 -38
Total VMT 571,499 575,327 571,534
Diff from Opt.B na +3,828 +35Source: Sacramento Area Council of Governments, October 2009.