Comparing Aggregate Trip- Based and Disaggregate Tour-Based Travel Demand Models: Columbus Highway...

Comparing Aggregate Trip-Based and

Disaggregate Tour-Based Travel Demand Models:

Columbus Highway Results

Research Project Overview• Research led by University of Texas-

Austin with AECOM, John Bowman, Mark Bradley & Ram Pendyala

• Main objective: examine the performance of the trip-based and tour-based frameworks for Columbus in the context of a before-and-after project analysis

Major Tasks

• Update trip-based model to resolve differences in estimation datasets, TOD, geographic coverage and other areas

• Develop 1990, 2000 and 2005 scenarios (including socio-economic data, networks, traffic counts, etc.)

• Compare models’ regional-level results to Census (1990, 2000), Household Interview Survey (1999), ACS (2005)

• Decide on study projects• Compare models’ project level-results

Brief Model Comparison

Trip-Based Model Tour-Based Model

Unit of Travel Trip Tour

Travel Aggregation

Zonal-level Person-level

Estimation Datasets

GenerationDistributionMode Choice

1999 HIS1999 HIS1993 COTA On-Board

1999 HIS1999 HIS1993 COTA On-Board + 1999 HIS

Geographic Coverage

1877 zones across 7 counties

Time-of-Day FidelityGenerationDistributionMode ChoiceAssignment

DailyDailyPeak/off-peak4 time periods

1-hour blocks4 time periods4 time periods4 time periods

Base Year(s) 2000, 2005 2000, 2005

Validation - VMTTOUR MODEL Observed Traffic Modeled Traffic Percent Difference

Facility Type # Links CountCount VMT

VolumeModel VMT

Volume VMTMax.

% VMT%

RMSE

1 Interstate 155 7,557,083 7,716,241 7,554,692 7,404,023 0% -4% 7% 17%

2 Expressway 96 2,247,915 1,610,448 2,205,784 1,597,832 -2% -1% 10% 18%

3 Arterial 2,521 22,159,792 6,385,080 22,471,650 6,321,376 1% -1% 10% 32%

4 Collector 1,531 3,962,091 1,654,805 3,732,848 1,553,047 -6% -6% 15% 56%

5 Local 932 1,012,435 413,312 982,722 389,390 -3% -6% 15% 92%

Total 5,235 36,939,316 17,779,886 36,947,696 17,265,668 0.0% -2.9% 3% 37%

TRIP MODEL Observed Traffic Modeled Traffic Percent Difference

Facility Type # Links CountCount VMT

VolumeModel VMT

Volume VMTMax.

% VMT%

RMSE

1 Interstate 155 7,557,083 7,716,241 7,859,723 7,934,125 4% 3% 7% 13%

2 Expressway 96 2,247,915 1,610,448 2,313,518 1,676,435 3% 4% 10% 20%

3 Arterial 2,521 22,159,792 6,385,080 20,872,011 5,938,085 -6% -7% 10% 34%

4 Collector 1,531 3,962,091 1,654,805 3,673,546 1,537,975 -7% -7% 15% 57%

5 Local 932 1,012,435 413,312 948,324 390,552 -6% -6% 15% 92%

Total 5,235 36,939,316 17,779,886 35,667,122 17,477,172 -3.4% -1.7% 3% 37%

Validation - % RMSE

Model-to-Model Comparisons

• Trip distance by trip purpose

• Delta volume bandwidth plots– ∆ volume = Tour model – Trip

model

Comparison of Trip Length by Purpose

8

Delta Volume Bandwidth Plot1990

9


10


11

Regional-Level Results

• Vehicle ownership– Tour model performs better in Franklin

County– Trip model performs better in other counties

• Work flows– Both models generally perform the same,

except for inter-county movements where the tour model generally performs better

• Average work travel time– Both models generally perform the same

Findings from the Report

• Need to investigate why tour-based model systematically under-performs in vehicle ownership outside Franklin County

• Overall there are few major differences between the two models (slight overall edge to tour-based model?)

• It is difficult to make disaggregate model comparisons when the models have different units of travel– Translating units leads to inconsistencies at a disaggregate

level, making the tour-based model’s full range of potential benefits difficult to compare to trip-based models

• More comparisons between trip- and tour-based models are needed to verify these findings

Project-Level Analysis

• Polaris – IR 71/ SR 750 Polaris Parkway– Large retail and employment growth– Interchange and other roadway improvements

• Rome-Hilliard – IR 70/IR 270– Large land-use development– No roadway improvements

• Spring-Sandusky – downtown Columbus– No major land-use changes– Major roadway improvements

• Control area – IR 71 in southwest Columbus– No major land-use changes or roadway

improvements

All Study Areas

Spring-Sandusky Study

Area

Polaris Study Area

Hilliard-Rome Study Area

Control Area

Polaris - 1988

Polaris - 2008

Spring-Sandusky Study Area

Hilliard-Rome Study Area

Control Area

Volume to CountsPolaris – 1990

Red – Overassigned

Blue - Underassigned

Trip Tour




Trip

Tour




Trip Tour

Volume to CountsSSI – 1990



TripTour




TripTour




Trip

Tour

Design Forecasts

• Add 1 more “model”– Fratared a matrix of 1s to the Trip Ends

from the Tour model

Volume/Counts and Forecasts

• Polaris

IR 71 South of SR 750Count Trip Tour Trip Ends Trip Tour Trip Ends

1990 40400 48773 42827 145805 8373 2427 1054052000 104500 115352 101922 201255 10852 -2578 967552005 122730 139013 123209 257432 16283 479 134702

Growth Rate 13.9% 12.5% 12.7% 4.9% -1.4% -1.2% -9.0%

Volume Difference

IR 71 South of SR 750Count Trip Tour Trip Ends Trip Tour Trip Ends

1990 404002000 104500 98749 93461 99583 -5751 -11039 -49172005 122730 127923 119991 129175 5193 -2739 6445

Growth Rate 13.9% 14.4% 13.1% 14.6% 0.5% -0.8% 0.7%

NCHRP 255 Forecast Difference


• Spring-Sandusky Interchange

IR 670 West of US 23Count Trip Tour Trip Ends Trip Tour Trip Ends

1990 42718 52873 62615 104115 10155 19897 613972005 117860 126611 138121 278010 8751 20261 160150

Growth Rate 11.7% 9.3% 8.0% 11.1% -2.4% -3.7% -0.6%

Volume Difference

IR 670 West of US 23Count Trip Tour Trip Ends Trip Tour Trip Ends

1990 427182005 117860 113499 112786 197411 -4361 -5074 79551

Growth Rate 11.7% 11.0% 10.9% 24.1% -0.7% -0.8% 12.4%



• Rome-Hilliard

Rome-Hilliard Rd. Count Trip Tour Trip Ends Trip Tour Trip Ends

1990 14504 9349 8794 26238 -5155 -5710 117342005 23986 27551 23467 37630 3565 -519 13644

Growth Rate 4.4% 13.0% 11.1% 2.9% 8.6% 6.8% -1.5%

Volume Difference

Rome-Hilliard Rd. Count Trip Tour Trip Ends Trip Tour Trip Ends

1990 145042005 23986 34409 30962 24120 10423 6976 134

Growth Rate 4.4% 9.1% 7.6% 4.4% 4.8% 3.2% 0.1%



• Control Area

IR 71 South of Stringtown Rd.Count Trip Tour Trip Ends Trip Tour Trip Ends

1990 38804 34829 36823 46870 -3975 -1981 80662000 53780 50668 49657 66288 -3112 -4123 125082005 62460 56232 52769 67826 -6228 -9691 5366

Growth Rate 4.0% 4.2% 3.0% 3.1% 0.1% -1.1% -0.9%

Volume Difference

IR 71 South of Stringtown Rd.Count Trip Tour Trip Ends Trip Tour Trip Ends

1990 388042000 53780 53577 49635 51944 -203 -4145 -18362005 62460 60964 55050 58514 -1496 -7410 -3946

Growth Rate 4.0% 3.8% 2.8% 3.4% -0.2% -1.2% -0.6%


Speed ComparisonIR 71 South of Morse Rd

Speed Trip Tour Trip Ends Trip Tour Trip Ends Trip-TourNB 2000 62.06 2000 55.86 55.89 28.65 -6.2 -6.17 -33.41 -0.03

2009 69.30 2005 55.81 55.8 24.07 -13.49 -13.5 -45.23 0.011.3% 0.0% 0.0% -3.2% -1.3% -1.3% -4.5%

SB 2000 56.39 2000 55.85 55.94 34.45 -0.54 -0.45 -21.94 -0.092009 70.82 2005 55.72 55.88 27.39 -15.1 -14.94 -43.43 -0.16

Growth Rate 2.8% 0.0% 0.0% -4.1% -2.9% -2.9% -6.9%

Volume Difference

IR 71 North of Stringtown Rd.Speed Trip Tour Trip Ends Trip Tour Trip Ends Trip-Tour

NB 2000 65.96 2000 57.97 57.98 56.93 -7.99 -7.98 -9.03 -0.012009 66.73 2005 64.88 64.94 61.33 -1.85 -1.79 -5.4 -0.06

0.1% 2.4% 2.4% 1.5% 2.3% 2.3% 1.4%SB 2000 61.22 2000 57.98 57.99 57.58 -3.24 -3.23 -3.64 -0.01

2009 60.75 2005 64.93 64.95 63.58 4.18 4.2 2.83 -0.02Growth Rate -0.1% 2.4% 2.4% 2.1% 2.5% 2.5% 2.2%

Volume Difference

IR 670 E of Grandview AveCount Trip Tour Trip Ends Trip Tour Trip Ends Trip-Tour

EB 2000 70.6 2000 54 54 54 -16.6 -16.6 -16.6 02009 67.44 2005 55.9 55.95 51.96 -11.54 -11.49 -15.48 -0.05

-0.5% 0.7% 0.7% -0.8% 1.2% 1.2% -0.3%WB 2000 62.97 2000 54 54 54 -8.97 -8.97 -8.97 0

2009 65.81 2005 55.99 56 54.75 -9.82 -9.81 -11.06 -0.01Growth Rate 0.5% 0.7% 0.7% 0.3% 0.2% 0.2% -0.2%

Volume Difference

Conclusions

• With an aggregate assignment, there isn’t much difference between the demand models for your run-of-the-mill project traffic forecasts.

• Biggest difference is in what questions your model can answer

• Develop a model that answers questions that are being asked in your region.– Use your crystal ball to determine what

questions are likely to be asked over the next 20 years.

Contacts

• Greg Giaimo – ODOT – [email protected]

• Rebekah Anderson – ODOT – [email protected]

• Zhuojun Jiang – MORPC – 614-233-4147• Chandra Bhat – UT at Austin

[email protected]

• Dave Schmitt – [email protected]

Comparing Aggregate Trip- Based and Disaggregate Tour-Based Travel Demand Models: Columbus Highway...

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