MORPC Model Comparison Project Trip vs. Tour Model.

MORPC Model Comparison ProjectTrip vs. Tour Model

Research Project

• Led by Ohio DOT and initiated in 2008• Main objective: examine the performance

of the MORPC trip-based and tour-based frameworks in the context of a before-and-after project analysis

• ODOT, MORPC, OKI and NOACA are looking to obtain a clearer picture of the potential practical benefits of tour-based models in the context of assessing projects and policies

Research Tasks

1. Understand model differences2. Determine analysis methodologies

and data requirements3. Select study projects for before/after

analysis4. Determine data collection projects5. Prepare models and model data6. Run models, analyze output and

observed conditions

Requirements for an Analogous Comparison• Common analysis years

– Using 1990, 2000, 2005 (due to better 1990 SE data than 1995)

• Identical estimation datasets• Isolate supply-side differences• Isolate demand-side differences

• Borrowed a Trip Model from OMS

New Trip Model Formulation

Estimation Datasets

• Estimate new Trip Generation and Gravity Distribution Models with the 1999 HIS

• Trip model will use mostly identical SE data as the tour model

• Update mode choice model to use IVT, OVT and wait coefficients from tour model

• Other coefficients will be scaled

Mode Choice

• Mode choice– Trip model uses nested logit

structure based on 1993 on-board survey

– Tour model uses mostly multinomial structures based on 1999 HIS + 1993 on-board survey - Also adheres to FTA New Starts parameter guidelines

Model Areas

Demand-side Differences

• 4-period assignment• External and CMV models are based on SE

data and network impedances, so they would change with different assignments– Solution: hold trip tables constant across the

models and alternatives• Equilibrium assignment closure rates can

vary mode choice impedances and final highway volumes– Solution: apply very high closure rate to both

models

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

Other Considerations

• Trip Model is fairly simplistic– No peak spreading– No vehicle ownership– Daily level generation and

distribution– Gravity distribution model– 1 iteration of feedback to mode

choice

Proposed Before/After Projects

• Spring-Sandusky interchange– Large-scale freeway project– Project is completed and

subsequent land-use development has stabilized

• Polaris– Medium-scale freeway interchange

project– New and subsequently modified

interchange in rapid growth area

Spring-Sandusky

Spring-Sandusky

Polaris - 1988

Polaris - 2008

Proposed Before/After Projects

• Systemwide transit analysis– 35% decline in transit service 2001-2005– Trunk routes virtually unchanged, with

suburban service reduced • Hilliard-Rome Road Area

– High growth area, but no substantial transportation changes

– Land use changes have now largely subsided

• Control Site – IR 71 South of the CBD

Traffic Volumes

• Why we care about traffic volumes– 100-200 projects a year that use

the model’s traffic volumes

Contact Information

Rebekah Anderson – [email protected]

Greg Giaimo – [email protected]

David Schmitt – [email protected]