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 / 2003Chris Petro, AICP

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

Presentation Outline

What are we modeling – study area backgroundWhere 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

Geographic Overview

Geographic Overview

Geographic Overview

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

Study Area &Transportation Network Characteristics

Classification Mileage

Interstate 134.1 mi.

Freeway 25.8

Prin. Arterial 206.1

Minor Arterial 325.5

Collector 380.5

Total: 1072.0Gaming

Barksdale AFB

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

Study Area &Transportation Network Characteristics

Classification Mileage

Interstate 134.1 mi.

Freeway 25.8

Prin. Arterial 206.1

Minor Arterial 325.5

Collector 380.5

Total: 1072.0Gaming

Barksdale AFB

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

Study Area &Transportation Network Characteristics

Gaming

Barksdale AFB

Model Conversion Experience… Where have we been

1990 Long Range Plan - TRANPLAN based travel demand model200 TAZs – US Census Blk. Group Geography (hardcopy maps)Physical network features were NOT spatially referenced (x-y grid) – were drawn to scale1991 links/TAZs digitized in ATLAS GIS software (1990 TIGER spatial accuracy)

Classification Mileage

IState/Freeway 47.6 mi.

Prin. Arterial 113.1

Minor Arterial 135.5

Collector 399.5

Total: 695.7

Urban Pop.: 284,928(US Census 1990)

Land Area: 499 Sq. Mi. 1990 US Census defined

Urban Area Boundary (UZA)

1990 MPOPlanning Study Area

1990 Study Area Stats.

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

TRANPLAN Model Details

1990 Modeled Network Features

1990 Modeled Network Features

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”

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

TransCAD Data Tools

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)

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

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

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

QC 1990 TAZ boundaries against the more spatially accurate 2000 Base Network links (centerlines)

Salvage Effort Quality Control (QC)

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

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?

Detailed Technical Questions – Session #1

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 featuresAccount for our unique future development scenarios (Statewide Plan Project Funding vs. No Statewide Funding)

Model Development Philosophy Statewide Plan Funding Track

With Statewide Funding

Model Organization(Two Track Funding Scenarios)

Without Statewide Funding

Base Year (2000)

2005 E+C Network

2015 Network

2025 Network

Base Year (2000)

2005 E+C Network

2015 Network

2025 Network

MPO SWP Projects

Model Development Philosophy Statewide Plan Funding Track

I-20 Widen to 6 lanes

Improvements

Name Route

Limits 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-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

MPO SWP Projects

Current MPOPlanning Study Area

Study Area Stats.

Population: 350,000 (US Census 2000)

Land Area: 1805 Sq.Mi.

Zones & Networks

Base Year Data

Future Planning Data

Database

Base Year Future Year

Trip Generation

Estimate Zonal Productions/Attractions

Distribution

Predict Zonal Trip Interchanges

Modal Split

(not applied to this model)

Assignment

Predict Routes Taken between Zones

Evaluation

Base Year Future Year

Valid

ati

on

P

roce

ss

Model Methodology Outline

* Mirrors our 1990 Model Methodology

*

*

*

*

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)

1990 to 2000 Network Comparison

- Additional 376.3 miles

- 36 New TAZs

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 RepresentationLADOTDCity of ShreveportCity of Bossier CityShreveport Chamber of CommerceBossier Chamber of CommerceShreveport Metro. Planning CommissionBossier City Metro. Planning CommissionSporTranCommunity Development - Bossier CityCommunity Development - ShreveportCaddo ParishBossier ParishBio Medical Research FoundationLSU Business CenterLSU Department of EconomicsSWEPCOShreveport Bossier PortHibernia BankVintage RealtySealy & CompanyCaddo Parish SchoolsBossier Parish Schools

Delphi Committee

Delphi Zones

Delphi Results

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 RepresentationLADOTDCity of ShreveportCity of Bossier CityShreveport Chamber of CommerceBossier Chamber of CommerceShreveport Metro. Planning CommissionBossier City Metro. Planning CommissionSporTranCommunity Development - Bossier CityCommunity Development - ShreveportCaddo ParishBossier ParishBio Medical Research FoundationLSU Business CenterLSU Department of EconomicsSWEPCOShreveport Bossier PortHibernia BankVintage RealtySealy & CompanyCaddo Parish SchoolsBossier Parish Schools

Delphi Committee

Delphi Zones

Delphi Results

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-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

Undertaken – 11/99 Purpose: Update

1989 survey O-D data Quick QC – use

TransCAD’s desire line functionality

  Regional Trip O-Ds

 External-Internal vehicle trips (EI)

 External-External (through veh. trips) (EE)

ExternalTravel Survey

QC Ext Survey Data

Undertaken – 11/99 Purpose: Update

1989 survey O-D data Quick QC – use

TransCAD’s desire line functionality

  Regional Trip O-Ds

 External-Internal vehicle trips (EI)

 External-External (through veh. trips) (EE)

ExternalTravel Survey

$

$

$

$

$

$

$

$

$

$ $

$

$

$

$

$

$

$ $ $

$

$

$

$

$

$

$

CADDO COUNTY

BOSSIER COUNTY

27

26

25

24

23

22

21

20

19

18

1716

15

14 13

12

11

10

9

8

7

6

5

4321

74.2%

25.8%

QC Ext Survey Data

Undertaken – 11/99 Purpose: Update

1989 survey O-D data Quick QC – use

TransCAD’s desire line functionality

  Regional Trip O-Ds

 External-Internal vehicle trips (EI)

 External-External (through veh. trips) (EE)

ExternalTravel Survey

$

$

$

$

$

$

$

$

$

$ $

$

$

$

$

$

$

$ $ $

$

$

$

$

$

$

$

CADDO COUNTY

BOSSIER COUNTY

27

26

25

24

23

22

21

20

19

18

1716

15

14 13

12

11

10

9

8

7

6

5

4321

I-20 West External-Local Movements

QC Ext Survey Data

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

Trip Purposes

Home-based work person trips (HBW)

Home-based non-work person trips (HBNW)

Non-home-based person trips (NHB)

Truck and taxi vehicle trips (TRTX)

Vehicle Trip Production Rates by Trip PurposeHomebased Work Example

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

4 0.954 1.503 2.173 2.356 2.533

5 1.230 1.940 2.788 3.011 3.304

Example Prod. Rates

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

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

Utilized User Equilibrium Assignment

Process Factors– Requires trip matrices

from trip distribution– Requires a QC’d

network

Calibration / Validation ProcessPerformance Indicators

Reasonable Trip Loadings

ClassificationFreeways 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

Study Area Percent Error Total ground counts compared to total

assignments for all screenline locations (<5%): our model 2.2%

1990 Model 2000 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

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

Not comparing TransCAD to TRANPLAN Checking assignments for reasonableness

1990 - Model Assignment 2000 - Model AssignmentObserved FINAL Diff % Observed FINAL Diff %

LOCATION Count Adjust. (FINAL-Obsv) Count Adjust. (FINAL-Obsv)

Red River Screenline:

I-220 11,610 12,629 8.07% 22,396 21,939 -2.08% U.S. 79/80 (Texas St. Br.) 10,240 10,459 2.09% 30,337 30,882 1.76% I-20 91,130 88,800 -2.62% 108,048 107,910 -0.13% LA 3032 (S'Port-Bark. Br.) 28,450 31,877 10.75% 33,001 30,633 -7.73% LA 511 (J. Davis Br.) 18,110 16,970 -6.72% 31,528 30,374 -3.80%

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 Uses in Support of Plan

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

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)?

Detailed Technical Questions – Session #2