Adopting Innovative MethodsFor Planning

Ken Cervenka, P.E., AICPNorth Central Texas Council Of Governments

For TRB Workshop 111:

Innovative Travel Models: Proof of ConceptWashington, D.C.January 9, 2005

Agenda

Background (About NCTCOG)

So What Holds People Back?

What I Wish Would Happen

Thoughts To Provoke Discussion

Current NCTCOG Modeling

TransCAD Platform

5,000 Square Miles / 4,874 Zones

Fully-Batched Graphical User InterfaceBut Humans Must Still Analyze/Interpret TheResults (And Make Final Decisions)

Four-Step Process

TRIP GENERATION

TRIP DISTRIBUTION

MODE CHOICE

ROADWAY ASSIGNMENT

TRAVEL TIMECONVERGENCE

TRANSIT ASSIGNMENT

NO

YES

ZONE LAYERDEMOGRAPHIC INFORMATION

ROADWAY NETWORK

TRANSIT NETWORK

LOO

P

ROADWAY SKIMS

TRANSIT SKIMS

INPUT

PROCESS

DECISION

4,536,010

6,671,351

4,848,237

5,650,339

7,952,0708,503,146

0

1,000,000

2,000,000

3,000,000

4,000,000

5,000,000

6,000,000

7,000,000

8,000,000

9,000,000

10,000,000

1995 2000 2005 2010 2015 2020 2025 2030 2035 2040

Previous Plan Demographics (Mobility 2025 Update) New Plan Demographics (Mobility 2025, 2004 Update)

(Previous Plan)

(New Plan)

Total Population Within The Dallas–Fort Worth Metropolitan Area

What Happens Next For NCTCOG

Applications TrainingStaff / Other AgenciesCertify Consultants?

Document The “Whys” Of Our Model Assumptions

More (And More) Output SummariesTables, Graphs, Maps

Integrated GIS Database EnvironmentMulti-Year Roadway/Transit Network Coding

Network Coding EnvironmentAgency's

ArcGIS LayerTransCAD Multi-

Year Network

Roadway/Transit Corridor Study

Agency's ArcGIS Layer

TransCAD Multi-Year Network

Alternatives

Agency's ArcGIS Layer

TransCAD Multi-Year Network

Final Recommendations

UpdatesUpdates

Updates

Checks

Checks

Updates

Checks

(Do Once)(Frequently)

GIS Database Integration

TransCAD Multi-Year Network

ArcGIS TIP/AQ Database and

Layer

ArcGIS Multi-Year Integrated

Layer

Other Databases/LayersTraffic Counts (Access)ITS Data (SQL)Skycomp Data (Access)GPS-Based Travel TimesAccidentsAt-Grade RR CrossingsIntersection Details

Export

Web-BasedInteractiveDisplays

What Happens Next (Cont.)

Destination Choice/Gravity Model Comparisons

Expanded Model Area (8,000+ Square Miles)

Update Or Replace Land Use Model (Metropilus)

Coordination With TxDOT Statewide Analysis Model

Sensitivity Tests Of Activity-Based Model (CEMDAP)UT-Austin, NCTCOG, TTI, Texas DOT

So What Holds People Back?(Impediments To Progress)

Unclear How Much Current Tools May Be Causing Bad Decisions About New/Expanded Roadways And Transit Service

Also Unclear How Advanced Models Would Have Responded

Do We Trust Researchers/Developers Who Tell Us TheyHave Much Better Tools Ready For Our Investment

The Real Cost, Timeframe, Ease Of Use, etc.

Pressure For Speed In Model Runs, Ease Of Use, And (Sometimes) Ease Of Interpretation

Impediments To Progress (Cont.)

How Much Will It Cost?

How Long Will It Take To Get The Product?

How Long Will It Take To Run The Product?

How Useful Will Be The Model Results?Will They Make Sense To The Decision Makers?Is There Something Else I Should Have Done?

Impediments To Progress (Cont.)

Staff Limitations (Consultants)How Many In The Available Contractor Pool Know How To

Implement Anything Other Than Four-Step Models?

Staff Limitations (MPO/DOTs)Lower Public Agency Salaries Often Result In Progressive

Thinkers/Champions Switching To Consultant JobsYes, The Money Is Higher Elsewhere—But A Potential Dead End

For Actual Advancement Of The Practice!

Quality Of Local Survey Data/Demographics/NetworksA Model Estimated/Calibrated From Garbage Is Still Garbage

What I Wish Would Happen

We Need Clear Information As To Where Things Stand With Advanced Model Readiness

Rigorous Peer-Reviewed Examination Of Implemented ModelsEven Estimated (Non-Calibrated) Models Can Be Sensitivity

Tested

Major Issues For ResolutionCheck For Spatial/Temporal TransferabilityNeed Realistic Costs/Timeframes For Improvements

Pooled Funding For Applied Research Leading ToImplementation

MPO (Or MPO/DOT) Consortium

Sensitivity Tests (Examples)

Think Of These As Attempts To De-Mystify ComplexModeling Assumptions

Area-Specific Increase/Decrease Of Input VariablesCheck Local/Regional Change In Travel PatternsCheck Local/Regional Change In Vehicle Miles And Hours Of

TravelCheck Local/Regional Change In Transit Passenger Miles And

Hours Of TravelPerform Same Tests With Four-Step Model

Universally-EstimatedAnd Locally Calibrated Model

Competitive Procurement Of Multi-Disciplinary TeamUniversities, Consultants, Software VendorsIndependent (And Paid) Expert Review PanelIdentify Realistic MilestonesQuarterly Meetings For Sponsors To See ProgressPublic Exposure To (Help) Keep Everyone Honest

Pooled Model Estimation Data SetsConsistent Survey Data, LOS (Skims), And Area Characteristics

(Context Variables)Across Several Regions AND Across Time Within Regions

Desired Results For PooledFunding Effort

Applied Research Conducted In An Orderly FashionBoth Minds And Funds Are Being PooledMay Have Many Market Segments And Complex Equations

That Could Be “Collapsed” For Some Implementations

Each Model Calibration/Validation Effort BuildsUpon Successes/Failures Of Previous Implementations

Provide Significant Support For New ResearchBut Discourage A Start-From-Scratch MentalityFull Documentation Of Results A Criteria For More Funding

Thoughts For Discussion:Discrete Choice Methods

How Variable Is Value Of Time (Time vs. Cost)?Work And Non-Work VariationsType Of Work (i.e., Flexibility In Arrival Time)Decision Stage (Home Location vs. Activity Location vs. Mode

Choice vs. Path Choice)

Does The Quality Of Time Vary?In-Vehicle vs. Transit Wait Time (Yes)Transit In-Vehicle vs. Auto In-Vehicle TimeReliability Of Transit Service And Auto Times

Thoughts For Discussion:Land Use Modeling

Comparisons Have Already Been Done, But:Should A Peer Review Group Define Tests, Review Results, And

Figure Out Where Things Stand?

Impacts Of Travel Accessibility Versus All ElseAre The Right Sensitivities In Place?

Could A “Universal Model” Be Developed?Across-Region And Across-Time DataUniversal Estimation / Local Calibration

Thoughts For Discussion:Activity-Based Modeling

What Can Be Learned From RigorousExamination Of Existing Implementations?

Portland MetroSan Francisco CountyNew York (NYMTC)Columbus (MORPC)Florida (AMOS)

Do We Know What Sensitivity Tests Are Needed?

Thoughts For Discussion:Dynamic Traffic Assignment

(And Traffic Simulation)

Why Do So Many Different Models Exist?A Flavor Of The Month Club?

Are These Intended For Both Short- And Long-Horizon Traffic Operations Analysis?

If Forecasted Demand Far Outstrips Supply, WillAssignment Results Be Useful?

High V/C Ratios In Current Assignments Can Serve As“Red Flags” For Detailed Analysis

Thoughts For Discussion:Microsimulation

Are Computer Processing Times Reasonable?

Can Issues Of Variation Be Handled In RegularModel Applications Work?

What Quality Is Needed For The Network AndDemographic Input Data?