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Development of Northwest Louisiana’s Travel Demand Model. … Model Conversion from a Small/Mid-Size MPO Perspective. Florida Model Task Force Meeting – November 12 th – 13 th / 2003 Chris Petro, AICP Tran. Plan. Mgr. – NW Louisiana Council of Governments. Presentation Outline.

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development of northwest louisiana s travel demand model

Development of Northwest Louisiana’s Travel Demand Model

… Model Conversion from a

Small/Mid-Size MPO Perspective

Florida Model Task Force Meeting – November 12th – 13th / 2003

Chris Petro, AICP

Tran. Plan. Mgr. – NW Louisiana Council of Governments

presentation outline
Presentation Outline
  • What are we modeling – study area background
  • Where have we been and where are we going …conversion experience

? – Answer submitted technical questions part 1

  • Static model development – TransCAD (Brief)

? – Answer submitted technical questions part 2

  • Model demonstration
study area transportation network characteristics
Study Area &Transportation Network Characteristics
  • Area Interstates: 49, 20, & 220 (a circumferential route); future I-state projs: I-49 N/S and I-69
  • EPA Designated - “Attainment” For AQ
  • SporTran – public trans. (approx. 3 mil. pass./year)
  • Special Generators

Gaming

Barksdale AFB

study area transportation network characteristics7
Study Area &Transportation Network Characteristics
  • Area Interstates: 49, 20, & 220 (a circumferential route); future I-state projs: I-49 N/S and I-69
  • EPA Designated - “Attainment” For AQ
  • SporTran – public trans. (approx. 3 mil. pass./year)
  • Special Generators

Gaming

Barksdale AFB

study area transportation network characteristics8
Study Area &Transportation Network Characteristics
  • Area Interstates: 49, 20, & 220 (a circumferential route); future I-state projs: I-49 N/S and I-69
  • EPA Designated - “Attainment” For AQ
  • SporTran – public trans. (approx. 3 mil. pass./year)
  • Special Generators

Gaming

Barksdale AFB

model conversion experience where have we been
Model Conversion Experience… Where have we been
  • 1990 Long Range Plan - TRANPLAN based travel demand model
  • 200 TAZs – US Census Blk. Group Geography (hardcopy maps)
  • Physical network features were NOT spatially referenced (x-y grid) – were drawn to scale
  • 1991 links/TAZs digitized in ATLAS GIS software (1990 TIGER spatial accuracy)
1990 mpo planning study area
1990 MPOPlanning Study Area
  • Urban Pop.: 284,928

(US Census 1990)

  • Land Area: 499 Sq. Mi.
  • 1990 US Census defined Urban Area Boundary (UZA)

1990 Study Area Stats.

tranplan model details
TRANPLAN Model Details
  • Base Year (1990) Socio-Economic Data:

1990 US Census (pop. and housing)

Dept. of Labor (employment)

  • EI and EE trips estimated from multiple regression eq. relating 1989 travel survey data to the 1990 socio-econ. data
  • Custom Trip Gen model (solve A solve P)
  • “Gravity Model”
  • Equilibrium assignment

technique

why did we convert internal justification

Direct Data Access for:

• ESRI Shapefiles• MapInfo TAB files• Oracle Spatial• dBASE/FoxPro/X-base• Text and binary data tables

• Raster files including SPOTView, TIFF, GeoTIFF,  Orthophoto, ECW, and MrSID• All ODBC sources (including Access, Btrieve,  DB2, INFORMIX, INGRES, Interbase, NetWare,  SQLBase, SQL Server, Sybase)

Import/Export Support for:

• ARC/INFO• ArcView• Atlas GIS• AutoCAD DXF• Defense Mapping VPF and ITD• Digital Line Graph

• ETAK MapBase• Excel• Intergraph DGN• MapInfo MIF/MID• Ordnance Survey NTF• TIGER/Line

Why Did We Convert? (Internal Justification)
  • Timing Issues – Long Range Plan Update
  • TRANPLAN file organization was becoming cumbersome
  • TransCAD Best At Blending Travel Model Development With GIS (meshed well with our GIS effort)
  • Conversion and Import/Export Tools
  • Reasonable “Learning Curve”

TransCAD Data Tools

why did we convert external forces
Why Did We Convert? (External Forces)
  • Louisiana Planning Council (LPC) Through LADOTD Purchased TransCAD For All Urban Area Models (8 MPOs)
  • LADOTD Initiated Their Long Range Plan – TranCAD Utilized For Their Model Component
  • Other State DOTs and MPOs Successful Implementation
  • U.S. DOT Endorsement
salvage effort physical network
Salvage Effort (Physical Network)

Since we expanded our Study Area… nearly had to start from scratch

  • The 1990 TAZ boundaries were still valid

- Define new TAZs for expanded Study Area

  • 1990 links were scrapped for more geospatially accurate and topologically correct links developed from the Regional GIS centerline features
  • No 1990 TAZ/External Sta. centroids were salvaged
  • Bottom line – New link/TAZ features built from existing GIS dataset NOT directly from TRANPLAN
salvage effort network attributes socio economic data
Salvage Effort (Network Attributes / Socio-Economic Data)
  • We associated (tag within distance function) the 1990 link attribute data to the new TransCAD base network, but we utilized the existing1990 link structure that had been already built and referenced in our GIS
  • Reused the link capacity table (1985 HCM lane capacity by facility type)

Tip: A form of triangulation (3 or more known points) can be used to project unreferenced spatial features – usually through a GIS extension or add-on projection utility

salvage effort quality control qc
Salvage Effort Quality Control (QC)
  • QC 1990 TAZ boundaries against the more spatially accurate 2000 Base Network links (centerlines)

Model development geocoding activities O-Ds from External Travel Survey or Attraction Model locating employment

FYI: Planning to use spatial analysis techniques (e.g. geocoding)

make sure all the datasets have comparable spatial accuracy

detailed technical questions session 1
Detailed Technical Questions – Session #1

Developing a TransCAD database from TRANPLAN ASCII files

1) What process was set in place to make sure the functional classification and area type classification of roadways was consistently and correctly converted?

2) How are speeds and capacities converted to maintain consistency between the TRANPLAN platform and the TransCAD platform?

3) What was done to ensure that the centroid loadings were put in the same locations and had the same number of connection for each zone?

4) How was the database structure set to ensure that future year networks were consistent with and correctly built upon the base year network?

5) How is the database maintained to preserve the integrity of the base network for each of the model years so that alternatives are never mixed with the base data set?

model development philosophy where are we going
Model Development Philosophy… Where are we going
  • Limited resources – “Start simple and embellish later”
  • Follow proven methodology – UTP Four-Step Modeling Process (1990 Model)
  • Modeled network accurately represents transportation features
  • Account for our unique future development scenarios (Statewide Plan Project Funding vs. No Statewide Funding)
model development philosophy statewide plan funding track

Model Organization

(Two Track Funding Scenarios)

Without Statewide Funding

With Statewide Funding

Base Year (2000)

Base Year (2000)

2005 E+C Network

2005 E+C Network

2015 Network

2015 Network

2025 Network

2025 Network

Model Development Philosophy Statewide Plan Funding Track

MPO SWP Projects

model development philosophy statewide plan funding track22

Name

Route

Limits

Improvements

Cost

Interstate 20

I-20

TX State line to Pines Road

Widen to 6 lanes

$ 75 M

Interstate 20

I-20

Red River Bridge and approaches

Widen to 8 lanes

50 M

Interstate 20

LA 3 to I-220 East

50 M

Interstate 49 North

I-49

I-220 to Ark State Line

New 4 lane interstate

363 M

Jimmie Davis Highway

LA 511

Clyde Fant Pkwy to Barksdale Blvd.

Replace bridge/widen to 4 lanes

50 M

I-20

Widen to 6 lanes

I-69

I-69

I-20 to US 171

New 4 lane interstate

380 M

Shreveport- Blanchard

LA 173

Roy Rd. to I-220

Widen to 4 lanes

18.5 M

North Lakeshore

Underpasses @ KCS Yard

2 new underpasses

10 M

Total

$ 996.5 M

* Goes against federal financial constraint

Model Development Philosophy Statewide Plan Funding Track

MPO SWP Projects

current mpo planning study area
Current MPOPlanning Study Area

Study Area Stats.

  • Population: 350,000 (US Census 2000)
  • Land Area: 1805 Sq.Mi.
model methodology outline
Model Methodology Outline

*

*

*

*

* Mirrors our 1990 Model Methodology

development physical network
Development: Physical Network
  • Based Upon Regional GIS Project referenced features imported into TransCAD
  • Links/Nodes - Topologically Correct (QC link direction and coding)
  • Expanded 1990 TAZ Structure To 2000 Study Area (TAZUP)
development socio economic data model

Delphi Representation

LADOTD

City of Shreveport

City of Bossier City

Shreveport Chamber of Commerce

Bossier Chamber of Commerce

Shreveport Metro. Planning Commission

Bossier City Metro. Planning Commission

SporTran

Community Development - Bossier City

Community Development - Shreveport

Caddo Parish

Bossier Parish

Bio Medical Research Foundation

LSU Business Center

LSU Department of Economics

SWEPCO

Shreveport Bossier Port

Hibernia Bank

Vintage Realty

Sealy & Company

Caddo Parish Schools

Bossier Parish Schools

Development: Socio-EconomicData Model
  • Base Year Data Sets: 2000 US Census (prods.) and Dept. of Labor Employ. Dbase (attracts.)
  • Tagged To TAZs
  • “Grow The Data” – The Delphi Method

Delphi Committee

Delphi Zones

Delphi Results

development socio economic data model27

Delphi Representation

LADOTD

City of Shreveport

City of Bossier City

Shreveport Chamber of Commerce

Bossier Chamber of Commerce

Shreveport Metro. Planning Commission

Bossier City Metro. Planning Commission

SporTran

Community Development - Bossier City

Community Development - Shreveport

Caddo Parish

Bossier Parish

Bio Medical Research Foundation

LSU Business Center

LSU Department of Economics

SWEPCO

Shreveport Bossier Port

Hibernia Bank

Vintage Realty

Sealy & Company

Caddo Parish Schools

Bossier Parish Schools

Development: Socio-EconomicData Model
  • Base Year Data Sets: 2000 US Census (prods.) and Dept. of Labor Employ. Dbase (attracts.)
  • Tagged To TAZs
  • “Grow The Data” – The Delphi Method

Delphi Committee

Delphi Zones

Delphi Results

development socio economic data model28
Development: Socio-EconomicData Model
  • Base Year Data Sets: 2000 US Census (prods.) and Dept. of Labor Employ. Dbase (attracts.)
  • Tagged To TAZs
  • “Grow The Data” – The Delphi Method

Delphi Committee

Delphi Zones

Delphi Results

development socio economic data model29
Development: Socio-EconomicData Model
  • Base Year Data Sets: 2000 US Census (prods.) and Dept. of Labor Employ. Dbase (attracts.)
  • Tagged To TAZs
  • “Grow The Data” – The Delphi Method

Delphi Committee

Delphi Zones

Delphi Results

external travel survey
ExternalTravel Survey
  • Undertaken – 11/99
  • Purpose: Update 1989 survey O-D data
  • Quick QC – use TransCAD’s desire line functionality

QC Ext Survey Data

external travel survey31
ExternalTravel Survey
  • Undertaken – 11/99
  • Purpose: Update 1989 survey O-D data
  • Quick QC – use TransCAD’s desire line functionality

QC Ext Survey Data

external travel survey32

I-20 West

External-Local Movements

ExternalTravel Survey
  • Undertaken – 11/99
  • Purpose: Update 1989 survey O-D data
  • Quick QC – use TransCAD’s desire line functionality

QC Ext Survey Data

trip generation component

Household Income Range

Household Size

1

2

3

4

5+

1

0.180

0.342

0.541

0.609

0.644

2

0.347

0.628

0.945

1.044

1.122

3

0.639

0.962

1.378

1.486

1.572

Vehicle Trip Production Rates by Trip Purpose

Homebased Work Example

4

0.954

1.503

2.173

2.356

2.533

5

1.230

1.940

2.788

3.011

3.304

Trip Generation Component
  • Estimate TAZ Ps/As
  • Trip generation rates by trip purpose will utilize standardized trips rates developed from the external travel survey
  • Production & Attraction models will use two way cross-classification

Example Prod. Rates

trip distribution component
Trip Distribution Component
  • Good Ol’ “Gravity Model”
  • Process Factors
    • Requires trips from trip generation model
    • Requires travel time matrix from defined network
modal split component
Modal Split Component
  • Not Applied To Our Model
  • Transit Trips Account for 0.3% - 0.4%/Year Of Total Trips
  • Can’t Justify Individual Choice Models (multinomial “Logit”)
trip assignment component
Trip Assignment Component
  • Utilized User Equilibrium Assignment

Process Factors

    • Requires trip matrices from trip distribution
    • Requires a QC’d network
calibration validation process performance indicators
Calibration / Validation ProcessPerformance Indicators
  • Study Area Percent Error

Total ground counts compared to total assignments for all screenline locations (<5%): our model 2.2%

  • Reasonable Trip Loadings

Classification

Freeways Less than 7%

Principal Arterials Less than 10%

Minor Arterials Less than 15%

Collectors Less than 25%

Source: FHWA Calibration & Adjustment of System Planning Models; December 1990

1990 Model2000 Model

6.6% 6.4%

1.5% 2.3%

1.4% 1.3%

5.6% 6.5%

Source: FHWA Calibration & Adjustment of System Planning Models; December 1990

calibration toolbox
Calibration Toolbox
  • Link penalties (Penalty.bin file)
  • Link speeds
  • Add and/or reconfigure placement of centroid connectors
  • “Detective Work” – uncover those coding errors (use TransCAD direction of flow and topology functionality)
the real test for success calibration 1990 model and 2000 screenline results
The “Real Test” For Success…Calibration - 1990 Model and 2000 Screenline Results
  • Not comparing TransCAD to TRANPLAN
  • Checking assignments for reasonableness
slide40

Model Uses in Support of Plan

  • Performance Measures to Assess Regional Transportation System
    • Vehicle miles traveled (VMT)
    • Vehicle hours traveled (VHT)
    • Average speeds
    • Volume to capacity (V/C) ratios
    • Screen line analysis
model status
Model Status
  • Finalized initial development (operational): 10/2003
  • Maintained and updated by myself and one other staff planner
  • Future model development

Conversion Observations

  • Didn’t salvage too much from TRANPLAN – made QC manageable from a smaller MPO perspective
  • Very positive conversion
detailed technical questions session 2
Detailed Technical Questions – Session #2

Conversion Process

1) Describe your experiences, touching on the time, effort and costs for converting and building your highway networks in TransCAD. Describe the same for the transit networks.

2) In hindsight are there processes and procedures that you would have done differently now having completed the conversion.

3) Are there programs and features in TRANPLAN that you could no longer perform once you converted to TransCAD?

Others

1) What is the protocol for file transfer (i.e. what needs to be included so that all the files that TransCAD creates and needs to operate are included when transferring datasets)?