# Presentation: 946969

## Overview

**Freight Modeling**

- Tianjia Tang, PE., Ph.D
- FHWA, Office of Freight Management and Operations
- Tianjia.Tang@FHWA.DOT.GOV
- Phone: 202-366-2217

## www.fmip.gov 

www.ops.fhwa.dot.gov/freight

**www.ops.fhwa.dot.gov/freight**

**For more information on freight ****	****modeling...**

## Presentation Outline

- 2: Modeling Approach
- 3: Method Classification
- 4: Challenges
- 5: Summary

**Presentation Outline**

## Modeling Objective

- 1: Economic development
- 2: Logistic and supply chain
- 3: Transportation planning and engineering

**Modeling Objective**

## Modeling Objective

- Private Business, Local, Regional, State, and Federal Government perform modeling for...

- _Three main areas:_
- 1: Economic development
- 2: Logistic and supply chain
- 3: Transportation planning and engineering

## Modeling Objective

- Private Business, Local, Regional, State, and Federal Government perform modeling for...

- _Three main areas:_
- 1: Economic development
- 2: Logistic and supply chain
- 3: Transportation planning and engineering

## Modeling Objective

- 1: Program level issues
- 2: Project level issues

**Modeling Objective**

## Modeling Objective

- 1)		Long Range Plan and Transportation Improvement Plan
- 2)		Conformity
- 3) 	Size and weight issues
- 4)		Modal diversion issue
- 5)		Others

**Modeling Objective**

## Modeling Objective

- 1)		Bridge/roadway design
- 2) 	Corridor study
- 3)		Modal diversion
- 4)		Weight station/parking optimization
- 5)		Hazmat
- 6)		Others

**Modeling Objective**

## Modeling Objective

- 1)		... amount of freight goes into my jurisdiction

**Modeling Objective**

- Bottom Line ...

## Modeling Objective

- 1)		... amount of freight goes into my jurisdiction
- 2)		... amount of freight goes out my  jurisdiction

**Modeling Objective**

- Bottom Line ...

## Modeling Objective

- 1)		... amount of freight goes into my jurisdiction
- 2)		... amount of freight goes out my  jurisdiction
- 3)		... amount of freight gets moved within my jurisdiction

**Modeling Objective**

- Bottom Line ...

## Modeling Objective

- 1)		... amount of freight goes into my jurisdiction
- 2)		... amount of freight goes out my  jurisdiction
- 3)		... amount of freight gets moved within my jurisdiction
- 4) 	... amount of freight goes through my jurisdiction

**Modeling Objective**

- Bottom Line ...

## Modeling Objective

- 1)		... amount of freight goes into my jurisdiction
- 2)		... amount of freight goes out my  jurisdiction
- 3)		... amount of freight gets moved within my jurisdiction
- 4)	   ... amount of freight goes through my jurisdiction
- 5) 	... ways/methods these freights get moved

**Modeling Objective**

- Bottom Line ...

## Future

- Present

- Past

**Modeling Objective**

## Modeling Objective

**... ****Know the target !**

**Modeling Objective**

## Modeling Approach

**Modeling Approach**

-  		... simulating behavior ... mechanistic based flow... empirical constructed...

- _...__given the long history, knowledge, and experiences on passenger demand travel modeling... _

## Modeling Approach

**Modeling Approach**

- 		...simulating behavior ... mechanistic based flow and empirical constructed

- ...given the long history on passenger demand travel modeling...

- 	1: Production
- 	2: Distribution
- 	3: Mode
- 	4: Assignment

## Method Classification

- 2: Trip generation rate based
- 3: Empirical statistical approach
- 4: Trend analysis

**Method Classification**

- Criteria: unique to freight models as compared with urban passenger models

## Commodity Based Method 

**Commodity Production****     ****($/Tonnage)**

**Commodity Distribution****     ****$/Tonnage**

**Commodity Mode Split  ****$/Tonnage**

**Vehicle Trip Generation**

**Traffic Assignment**

## Commodity Based Modeling Method 

**Commodity Production****     ****($/Tonnage)**

- 1: To estimate the production and consumption of
- 2: Units of measure: tonnage and $

-  a given commodity

## Commodity Based Modeling Method 

**Commodity Production****     ****($/Tonnage)**

- ...establish a base model/equation relating the production of a specific commodity to economic activities such as economic growth, employment, et al.

## Commodity Based Modeling Method 

**Commodity Production****     ****($/Tonnage)**

- _Three Key Issues:_
- 1: Commodity classification
- 2: Geographic level (size of the geographic area)
- 3: Economic activities: population, employment, payroll...

## Commodity Based Modeling Method 

**Commodity Production****     ****($/Tonnage)**

**Commodity Distribution****     ****$/Tonnage**

**Commodity Mode Split  ****$/Tonnage**

**Vehicle Trip Generation**

**Traffic Assignment**

## Commodity Based Modeling Method 

**Commodity Distribution****     ****$/Tonnage**

**Commodity Production****     ****($/Tonnage)**

**Commodity Consumption ****     ****($/Tonnage)**

## Commodity Based Modeling Method 

**Commodity Distribution****     ****$/Tonnage**

**Commodity Production****     ****($/Tonnage)**

**Commodity Consumption ****     ****($/Tonnage)**

- Commodity Specific
- Origin-Destination Data

## Commodity Based Modeling Method 

**Commodity Distribution****     ****$/Tonnage**

**Methods in OD Data Development **** **

- 1: Commodity Flow Survey: Gap Filling, disagregation, ...
- 2: Gravity Model: single constrained, double constrained, spatial interaction...

## Commodity Based Modeling Method 

**Commodity Distribution****     ****$/Tonnage**

- CFS OD Methods ... loglinear, ipf...

## Commodity Based Modeling Method 

**Commodity Distribution****     ****$/Tonnage**

**CPC Methods – gravity model ...**

## Commodity Based Modeling Method 

**Commodity Production****     ****($/Tonnage)**

**Commodity Distribution****     ****$/Tonnage**

**Commodity Mode Split  ****$/Tonnage**

**Vehicle Trip Generation**

**Traffic Assignment**

## Commodity Based Modeling Method 

- Rail Freight: STB’s annual waybill

**Commodity Mode Split  ****$/Tonnage**

- Water Freight: US ACOE annual S-S OD

- Truck Freight: most complicated

- Mode split data: Past, Current, and  Future?

## Commodity Based Modeling Method 

**Rail Freight: STB’s annual waybill **** **

**Water Freight: US ACOE annual S-S OD **** **

**Truck Freight: most complicated **** **

**Mode split data: Past and Current ? Future? **** **

- For a given commodity,
- Modal share typically
- remains
- u_nchanged!_

**Commodity Mode Split  ****$/Tonnage**

## Commodity Based Modeling Method 

**Commodity Production****     ****($/Tonnage)**

**Commodity Distribution****     ****$/Tonnage**

**Commodity Mode Split  ****$/Tonnage**

**Vehicle Trip Generation**

**Traffic Assignment**

## Commodity Based Modeling Method 

- 	_ __Tonnage data_
-     are converted to
-     _# of truck loads_

**Vehicle Trip Generation**

## Commodity Based Modeling Method 

- 1: Vehicle Inventory and Use Survey
- _[http://www.census.gov/svsd/www/02vehinv.html](http://www.census.gov/svsd/www/02vehinv.html)_
- 2: Examples of State and local data
-  _[http://www.scag.ca.gov/goodsmove/pdf/truckcnt_rpt.pdf](http://www.scag.ca.gov/goodsmove/pdf/truckcnt_rpt.pdf)_
-        _[http://www.sfta.wsu.edu/index.htm](http://www.sfta.wsu.edu/index.htm)_
-  _[http://www.sfta.wsu.edu/presentation/pdf/6_steeringCommitteJune13.pdf](http://www.sfta.wsu.edu/presentation/pdf/6_steeringCommitteJune13.pdf)_

**Commodity Based Modeling Method **

- 	Methods to Convert _Tonnage to_
- _Truck Loads_

## Commodity Based Modeling Method 

**Commodity Production****     ****($/Tonnage)**

**Commodity Distribution****     ****$/Tonnage**

**Commodity Mode Split  ****$/Tonnage**

**Vehicle Trip Generation**

**Traffic Assignment**

## Commodity Based Modeling Method 

- 1: all or nothing	2: stochastic user equilibrium 3: user equilibrium 4: capacity restrained  5: system optimum  6:others

**Traffic Assignment**

- _Uniqueness of Freight Transport ...__	_		the logistic industry	                    urban routing

## Commodity Based Modeling Method 

- Strength
- Based on fundamental economic activities...

- Weakness
- Exceedingly hard to validate and calibrate...

## Commodity Based Modeling Method 

- More than a dozen states or MPOs developed their freight models based on the commodity approach

- For more specific state model information, visit links provided at:                www.fmip.gov

## Trip Generation Rate 	Based  

**Trip Production**** **
**    **

**Trip Distribution**

**Traffic Assignment**

## Trip Generation Rate 	Based  

**Trip Production**** **
**    **

- # of truck trips generated per land use/employment/other activities...

## Trip Generation Rate 	Based  

- Gravity model                           Spatial intervention                  others

**Trip Distribution**

## Trip Generation Rate 	Based  

**Traffic Assignment**

- 1: all or nothing                             2: stochastic user equilibrium              3: user equilibrium                           4: capacity restrained                      5: system optimum                    6:others

## Trip Generation Rate 	Based 

- Strength
- Availability of field count data  ...

- Weakness
- Multimodal issue and forecasting issue  ...

## Empirical Statistical Methods 

- Completely different from the traditional 4 – steps modeling

- Number of vehicles N = f(land use, business locations, and other information)

## Empirical Statistical Methods 

**Dependent Variable N= Observed Traffic count number **

**Independent Variables**
**Function classification of the roadway, adjacent land use type, major business distance ....**

## Empirical Statistical Methods 

- Availability of truck count data  ...

- Weakness
- forecasting issue ...

**Empirical Statistical Methods **

## Trend Analysis 

- By examining the past traffic count data, and  making linear extrapolation of the data to obtain future data... more on a project level...

## Challenges

- 1: Modeling objective
- 2: Relationships between GDP and shipments
- 3: Economic sensitive modal data/model
- 4: Integration with other models

**Big Picture**

## Challenges

- 1: Effective and efficient data collection methods
- 2: Freight distribution algorithm
- 3: Freight traffic assignment algorithm
- 4: Model calibration and validation

**Technical**

## Summary

- 1: Objective
- 2: Approach
- 3: Types of Freight Models
- 4: Challenges

## That’s All. Thank You!