Transcript Document

NCTCOG And
“Next Generation” Modeling
Ken Cervenka, P.E., AICP
North Central Texas Council Of Governments
For
AMPO Travel Modeling Work Group Meeting
Kansas City, Missouri
September 28, 2004
Agenda
Current Modeling Environment
Next Steps—Near Term
Multi-Year Network Coding
Next Steps—Taking The Plunge
Total Population Within The
Dallas – Fort Worth Metropolitan Planning Area
10,000,000
7,952,070
9,000,000
(New Plan)
8,503,146
8,000,000
7,000,000
6,671,351
5,650,339
6,000,000
5,000,000
4,000,000
(Previous Plan)
4,848,237
4,536,010
3,000,000
2,000,000
1,000,000
0
1995
2000
2005
2010
2015
Previous Plan Demographics (Mobility 2025 Update)
2020
2025
2030
2035
2040
New Plan Demographics (Mobility 2025, 2004 Update)
Four-Step Modeling Process
DEMOGRAPHIC
INFORMATION
ZONE LAYER
TRIP
GENERATION
ROADWAY
NETWORK
ROADWAY SKIMS
TRANSIT
NETWORK
TRIP
DISTRIBUTION
LOOP
MODE CHOICE
ROADWAY ASSIGNMENT
TRANSIT SKIMS
NO
TRAVEL TIME
CONVERGENC
E
YES
TRANSIT
ASSIGNMENT
INPUT
PROCESS
DECISION
Trip Distribution
Gamma-Format Gravity Model (7 Purposes)
Four HBW Groups (Income Quartiles) – AM Peak
HNW (Non-Airport) – OffPeak
NHB (Non-Airport) – OffPeak
Trucks (Vehicles With Six Or More Tires) – OffPeak
Base Year Trip Table Factoring (6 Purposes)
HNW And NHB Airport Trips
Four External-Related Auto/Truck Trips
Market Segmentation
To Account For Differences In Commuter Behavior
Segmentation Basis (6 HBW And 6 HNW)
– Household Income (3)
• Low
• Medium
• High
– Vehicle Availability For A Household (2)
• Vehicles Less Than Persons
• Vehicles Greater Than Or Equal To Persons
Traffic Assignment
User Equilibrium Generalized Cost (Three 30-Iteration
Assignments)
A.M. Peak (6:30a – 8:59a: 2.5 hours)
P.M. Peak (3:00p – 6:29p: 3.5 hours)
OffPeak (18 hours)
Four Vehicle Classes Loaded Simultaneously
Drive Alone (Sees HOV-Toll Lanes As Tolled)
Shared-Ride (Sees All HOV Lanes As Free)
Shared-Ride (Doesn’t See Any HOV)
Trucks (Vehicles With 6 Or More Tires)
What Happens Next For NCTCOG
Training
NCTCOG Staff
Dallas Area Rapid Transit (DART) Staff
Other Agencies (Local/TxDOT)
Certification Of Consultants???
Model Implementers, Model Users, And Application Champions
Model Documentation
Include The “What” As Well As The “Why”
How To Run The Model/How To Understand The Model
What Happens Next (Cont.)
Possible Model Updates (0 - 3 Years)
More Output Report Summaries (Tables, Graphs, Maps)
Tests Of “Generic” Transit Skim/Mode Choice Procedures
LOGSUM Consistencies
Destination Choice Instead Of Gravity Model Trip Distribution
Expansion Of Modeled Area
Updated Land Use Modeling Tools
Additional Time Periods For Traffic Assignment
Coordination With TxDOT Statewide Analysis Model
Traffic Microsimulation For Subarea Operations Analysis
Transit Model Outputs:
Supply-Side Calculations
Number Of Coded Transit Lines
Roadway Network Links (Or Miles) With Transit
Total Physical Stops And “Transit Line” Stops
How Many Are Rail Stations
How Many Are Transit Park-And-Ride Locations
AM Peak And Mid-Day OffPeak Vehicle Miles And
Hours Of Travel
Population And Employment Within “Buffer” Areas
Transit Model Outputs:
Demand-Side Calculations
Transit Boardings And Alightings
By Mode, By Route, By Line, Or By Rail Station
For Weekday, Or For Each Of Four Assignments
Average Transfer Rates
Boardings, Riders, And Boardings Per Rider
Transit Passenger Miles And Hours
Rail Station Mode-Of-Access/Egress Summaries
Multi-Year Network Concept
One Link/Node Layer And One Transit Route Layer For
ALL Years
Contains ALL Streets
Essentially A 25-Year TIP!
Travel Model Network Extracted From All Streets Layer
Link And Route Selections Based On Start And End
Date Fields
Local And Non-MPA Street Links Excluded
Example: Blue Street Links Are
Extracted To Travel Model Links
Agency's "Master Roadway Layer"
Covers 16-County NCTCOG Area
2003 Digital Aerial Photos (Six Inch)
Example: Future-Year Interchange
Single-Point Intersection
Network Coding Environment
Agency's
ArcGIS Layer
(Do Once)
TransCAD MultiYear Network
(Frequently)
Roadway/Transit
Corridor Study
Updates
Updates
Agency's
ArcGIS Layer
Checks
Updates
Agency's
ArcGIS Layer
TransCAD MultiYear Network
Updates
Checks
TransCAD MultiYear Network
Checks
Alternatives
Final
Recommendations
GIS Database Integration
TransCAD MultiYear Network
Export
Other
Databases/Layers
ArcGIS TIP/AQ
Database and
Layer
ArcGIS MultiYear Integrated
Layer
Web-Based
Interactive
Displays
Traffic Counts (Access)
ITS Data (SQL)
Skycomp Data (Access)
GPS-Based Travel Times
Accidents
At-Grade RR Crossings
Intersection Details
Some Tough Issues
True Multi-Year Coding Is A Complex Environment
But Allows For Greater Consistency/Quality Control
Between Travel Model Years (And With TIP)
Traffic Counts And Detailed Roadway Data
(Including Traffic/Transit Projections):
Should We Put Everything On the Web?
Who Pays For The Initial Collection Costs?
Is Everything Free To The End User?
Should We Be Concerned About Possible Misuse?
Taking The Plunge:
Activity-Based (AB) Modeling
Maybe It Is “Put Up Or Shut Up” Time!
We Must Find Out Where Things Stand
Rigorous Sensitivity Tests Of Estimated Models
NCTCOG Can Test CEMDAP (UT-Austin/DFW Data)
Other Agencies Can Test Other AB Model Brands
Major Issues For Resolution:
Current Worthiness And Readiness Of AB Models
Spatial/Temporal Transferability Of Formulations/Estimations
If Not Ready: Realistic Costs And Timeframes For Improvements
Simple Sensitivity Tests (Examples)
Global Increase/Decrease Of Input Variables
Area-Specific Increase/Decrease Of Input Variables
Check Local/Regional Change In Travel Patterns
Check Local/Regional Change In Person Miles
Perform Same Tests With Implemented Four-Step Model
If Current Activity-Based Model
Formulations/Estimations Aren’t
Ready For The Real World:
Form An MPO (Or MPO/DOT) Consortium
Pooled Funding/Staff Resources
Pooled Survey Data And Network Skims
Identify Realistic Project Scope
Competitive Procurement Of University/Consultant Team
Independent Review Panel/Paid Workgroup Team
Quarterly Meetings For Sponsors To Measure Progress
Public Exposure May Help Keep Everyone Honest/Objective
Must Deal With Proprietary Software Issues
Desired Results For
Pooled Funding Effort
Applied Research Conducted In An Orderly Fashion
Does A New Theory/Latest Fad “Smell” Right?
Each Model Calibration/Validation Effort Builds
Upon Successes/Failures Of Previous Implementations
Provide Support For New Basic Research
Discourage A Start-From-Scratch Mentality
For E-Copy Of This Presentation
Type In This URL:
http://www.dfwinfo.com/trans/program_areas/travel_forecasting.html
Or Simply Google On:
“NCTCOG Travel Forecasting Program”
And Look Under “Travel Forecasting Presentations”