Presentation Transcript
ODOT Freight Modeling: ODOT Freight Modeling Presented to the Ohio Conference on Freight
Toledo, OH
September 18, 2007
By
Gregory Giaimo, PE
Ohio Department of Transportation
Context of Freight Modeling at State DOT’s: Context of Freight Modeling at State DOT’s Part of a larger statewide passenger and freight model
Developed primarily to study intercity highway corridors
Prior to 1990’s, very few such models due to lack of computers and methods
Since then about half the states have developed or are developing models
Statewide Model Status: Statewide Model Status Source: NCHRP Synthesis 358, Statewide Travel Forecasting Models
Freight Model Types: Freight Model Types Freight modeling is handled in one of four ways by state DOT models
None
Traditional “4 Step” Techniques
Commodity Based
Integrated Land Use/ Economic/ Commodity Based
Slide5: Source: TRB Electronic Circular E-C075: Statewide Travel Demand Modeling – A Peer Exchange
Statewide Models with No Freight Component: Statewide Models with No Freight Component
Some small states have models exactly analogous to urban passenger travel demand models with no freight model
Commodity Based Models: Commodity Based Models This approach models commodity flows
These flows are then converted to trucks, trains etc., generally using static mode and payload factors by commodity
This is the most common approach
Commodity Based Models (cont.): Commodity Based Models (cont.) Obtain their commodity flow data from the Commodity Flow Survey or the Transearch database
The Vehicle Inventory and Use survey is often used to develop payload factors
Integrated Land Use/ Economic/ Commodity Models: Integrated Land Use/ Economic/ Commodity Models This approach also models commodity flows
The main difference from the previous type is the explicit econometric and land use models which feed commodity flows to the transport models
Thus base year commodity flows are used to estimate these economic models instead of as direct model inputs
Ohio Model: Ohio Model
The five components directly related to the creation of freight flows will be hi-lighted:
Interregional Economic Model
Land Use Model
Activity Allocation Model
Aggregate Commercial Vehicle Model
Disaggregate Commercial Vehicle Model
Ohio Integrated Land Use/Economic/Transport Model: Disaggregate Household Synthesis and Employment Spatial Disaggregation Models Ohio Integrated Land Use/Economic/Transport Model Aggregate Commercial Vehicle Model Disaggregate Commercial Vehicle Model Interregional Economic Model Aggregate Demographic Model Land Development Model Activity Allocation Model Visitor Model Long Distance Travel Model Short Distance Travel Model Assignment Model
Model Modules: Model Modules Interregional economic model of production & consumption by economic sector reflecting national forecasts
Demographic model tied to economic activity reflecting migration and changes in population & household composition
Activity allocation model to distribute model area economic and demographic forecasts to analysis zones with the related flows of goods & labor among zones from which travel demands are derived
Land development model simulating developer behavior in response to demands & costs consistent with other development constraints
Personal & household travel model reflecting person & household characteristics, zonal characteristics, inter-zonal economic flows & transport system supply characteristics, 2 components: short distance which looks like an activity/tour based urban area model and long distance, also tour based with purposes: business, recreation, other
Model Modules: Model Modules Aggregate model of goods and services transport arising from economic and demographic activity by zone very similar to the typical DOT commodity based transport model
Disaggregate model of business-related person travel related to management functions, sales & support activities, provision of services and some short distance goods delivery.
Model of visitor travel within and into the model area made by non-residents
Transport system supply model incorporating air, intercity bus/rail, MPO transit & roadway networks with their corresponding level-of-service characteristics
Highway Network: Highway Network
Rail Network & Intermodals: Rail Network & Intermodals
Interregional Economic Model: Interregional Economic Model Establishes forecast flows of goods, services and labor (in $) between 14 regions of North America
Uses exogenous national economic conditions and production composite utilities from the previous time step of the lower level models
An inter-regional social accounting matrix based primarily upon IMPLAN data
Exogenous Economic Indicators: Nation Economic Forecast Variables National Economic Growth Exogenous Economic Indicators
Slide20: Industry Categories 1. Agriculture, Forestry, Fisheries
2. Primary Metals (Steel) 3. Light Industry 4. Heavy Industry 5. Transportation Equipment (Auto) 6. Wholesale 7. Retail 8. Hotel 9. Construction 10. Health 11. Transportation Handling 12. Utilities 13. Other Services 14. Grade School Education 15. Post-Secondary Education 16. Government
Land Use Model: Land Use Model Creates developed floor space by category by zone
Land develops (if possible) in response to increases in households and employment in the previous analysis year (see activity allocation model) but also due to:
Zoning
Flood plains
Slopes
School district quality
Water Service: Water Service
Flood Plains: Flood Plains
Severe Slope: Severe Slope
Activity Allocation Model: Activity Allocation Model Subdivides activity to 5000 traffic analysis zones
Population
Employment
Labor Flow
Commodity Flow
Uses transport utility equations relying on accessibilities and changes in developed land to redistribute activities from year to year
Activity Allocation Model: Activity Allocation Model Inputs include:
Regional flows from Interregional Economic Model
Floor space by category by TAZ from Land Use Model
Households from Aggregate Demographic Model
Transport costs from previous iteration of Transport Models
Aggregate Commercial Vehicle Model: Aggregate Commercial Vehicle Model With the commodity flows established, the aggregate commercial vehicle model itself is very similar to the commodity representation in other statewide models
Input is dollars of flow of goods and labor at the Traffic Analysis Zone (TAZ) level
Output is flows of trucks between TAZ’s
Aggregate Commercial Vehicle Model Flow Chart: Aggregate Commercial Vehicle Model Flow Chart Determine Mode Convert Goods Flows to Tons Total Dollars flows Determine Truck Type Determine Number of Truck Loads Determine Trucks by Hour of Day Based on traffic counts, conversion from annual to weekday assumes 300 equivalent week days per year. This value is obtained as follows: (52 * 5) weekdays plus (52 * 2 * 0.44) weekday equivalents for weekends minus 6 holidays. Trucks by type by hour by OD TAZ Fixed shares by commodity class, by distance for bulk commodities, mode choice model for inter-modal eligible commodities, based on CFS By commodity class and distance, from CFS By commodity class and distance, from VIUS By commodity class and truck type, from VIUS
Slide29: Truck Mode Shares by Distance and Commodity
Slide30: Dollar to Ton Conversion by Distance and Commodity
Slide31: Truck Type by Distance and Commodity
Slide32: Payload Factors by Distance and Commodity
Disaggregate Commercial Vehicle Model: Disaggregate Commercial Vehicle Model DCOM is designed to account for short distance commercial travel not related to the long distance shipping of freight (accounted for in ACOM)
Long distance business travel is accounted for in the Long Distance Travel model of the personal transport model since these trips were obtained in the special long distance travel survey
Disaggregate Commercial Vehicle Model: Disaggregate Commercial Vehicle Model Employs a tour based microsimulation of employees
Based on establishment surveys
Analogous to HH based tour based model but based at the place of work
Does not include route delivery vehicles
Slide35: Disaggregate Commercial Vehicle Model
Disaggregate Commercial Vehicle Model: Disaggregate Commercial Vehicle Model Employment categorized as:
Industrial
Wholesale
Retail
Transportation Handling
Service
Disaggregate Commercial Vehicle Model: Disaggregate Commercial Vehicle Model Trip purposes:
Service
Meeting
Goods (delivery)
Other (includes such things as stopping for lunch or fuel)
Outputs: Outputs
Forecast Volumes: Forecast Volumes
Traffic Flow Maps: Traffic Flow Maps District 2 Volumes Including Interstate District 2 Volumes Excluding Interstate
Slide41: Toll Sensitivity Analysis
Showing Volumes Changes
Slide42: Congestion Management By ODOT Districts For Ohio Counties Congestion Comparisons
User Costs by Alternative: User Costs by Alternative
Predicted Changes by Economic Sector: Predicted Changes by Economic Sector
Employment Forecasts: Employment Forecasts
Interaction of Ohio’s Economy with the Rest of the US: Interaction of Ohio’s Economy with the Rest of the US
Commodity Production: Commodity Production
Changes in Commodity Production: Changes in Commodity Production
Future Challenges: Future Challenges Modeling community would like to move to more detailed freight modeling based upon econometrics and supply chains
The main challenge that plagues this as well as current modeling efforts is the lack of geographically specific freight data
Top 10 Challenges Impeding Development of Freight Models by State DOT’s: Top 10 Challenges Impeding Development of Freight Models by State DOT’s Lack of DATA
Lack of DATA
Lack of DATA
Lack of DATA
Lack of DATA
Lack of DATA
Lack of DATA
Lack of DATA
Lack of Money
Lack of better theoretical formulations (but see 1-8 for why this is the case)
Questions?: Questions?