Freight TRB 0405

Implementing the FHWA Quick Response Freight Model in the Twin Cities : Implementing the FHWA Quick Response Freight Model in the Twin Cities Steve Wilson and Jonathan Ehrlich SRF Consulting Group, Inc. Dan Beagan Cambridge Systematics, Inc. Presented to Tenth Transportation Research Board Planning Applications Conference


Twin Cities Regional Freight Planning Model : Twin Cities Regional Freight Planning Model Objectives Approach/Methodology Calibration Considerations Applications


Objectives of the Project : Objectives of the Project Improve New Regional Travel Demand Models Better Reflect Impact of Trucks on Traffic Flow Lay Groundwork for Multimodal Freight Analysis and Modeling Connect to Statewide Freight Plan


Approach : Approach Based on FHWA Quick Response Freight Manual (1996) Make use of local data Make use of limited resources


Zonal Data : Zonal Data Employment Categories: Agriculture, Mining, Construction Manufacturing, Transportation, Communication, Utilities, Wholesale Trade Retail Trade Office and Services


Zonal Data : Zonal Data Employment Data Census vs. ES202 Freight Facility Inventory Quality Control Issues


Network Data : Network Data Highways Prohibitions Grade Vehicle Classification Counts Navigable Waterways Terminal Locations Locks and Dams Railways At-Grade Crossings Intermodal Terminals


Other Data : Other Data Freight Analysis Framework National Freight Flow Database Growth Rates for External Trips External Origin-Destination Survey Distribution of External Trips


Other Data : Other Data Light Commercial Vehicles In the regional model (large portion of NHBW trips) Difficult to quantify either in vehicle classification counts or in home-interview surveys MnDOT Light Commercial Vehicle Study, 1999


Four Step Model: Trip Generation : Four Step Model: Trip Generation By Vehicle Classification from QRFM Single Unit Combination ‘Light Commercial’ Function of Employment Type External Trips based on External Station Vehicle Classification Special Generator Capability


Four Step Model: Trip Distribution : Four Step Model: Trip Distribution Default gravity model friction factor curves from QRFM Modify trip table using matrix estimation Adjusted default curves based on estimated matrix


Four Step Model: Time of Day : Four Step Model: Time of Day Matches 24 time periods from Regional Model Constant factors for each time period for each vehicle classification Based on 24-hour vehicle classification count data


Four Step Model: Assignment : Four Step Model: Assignment Regional Model Assignment Equilibrium Assignment 24 Time Periods Five Assignment Purposes SOV, LCV, HOV, SU, CMB Three Paths SOV/LCV, HOV, Truck Passenger Car Equivalency


Validation : Validation Highway Link Volumes VMT


Calibration Considerations : Calibration Considerations Data Availability Vehicle Classification Internal Origin-Destination Trip Length Distribution External Station Data Commodity Data Concurrent Regional Model Calibration Regional Scope


Applications : Applications Forecasting Truck Traffic Pavement Design Development Impacts System Level Responses Modal Shift Impacts Value of Time/Benefit-Cost Truck Impacts on Congestion Grade Crossing Analysis


Recommendations for Further Improvement : Recommendations for Further Improvement Commercial Vehicle Tracking Survey National/Multi-State Commodity Flow Model External Truck Intercept Survey Vehicle Classification Data


Questions? : Questions?