Skip to main content

Fact Sheet

Incorporation of Inelastic Movement Level Demands in ORNIM



Start Date:  Jan 2006

End Date:
 Sep 2007






Problem Addressed:  

Models currently employed by the Corps are partial equilibrium annual models, with the waterway annual demand forecasts and implicit shipping plan modal splits (origin-destination-route) determined external to the modeling process. In the current Corps planning models, transportation price changes are explicitly modeled for the waterway routing, but are not modeled for alternate non-waterway routing; waterway shippers respond only when waterway prices rise above the least-cost all-overland transportation price which serves as the willingness-to-pay for water (barge) transportation. The shipper response is basically to either ship the annual demand tonnage by water or not, depending upon its least-costly all-overland route rate. It is understood, however, that: 1) the next best transportation option for a water-routed movement is not necessarily the least-costly all-overland routing option (e.g. pool hop, shift of origin and/or destination); 2) the water ship or not ship decision can be made at less than the annual volume size; 3) the water ship or not ship decision can be sensitive to not only water transportation costs, but also water transportation time changes; 4) the willingness-to-pay for barge transportation may exceed the least-cost all-overland rate; and 5) the waterway transportation demand can also be sensitive to land transportation cost and time changes. The desire is to more dynamically link equilibrium waterway traffic demand forecasts with shipper specific transportation cost and time sensitivities.





The first step of this work effort is to develop a design document for integrating the origin-destination-route choice shipper response functions into the USACE planning process. There are two methods of expanding the shipper response in the USACE modeling process: 1) input total origin-destination-commodity demands (instead of unconstrained waterway traffic demands) into ORNIM and expand ORNIM (a Tier 3 model) with the Train-Wilson origin-destination-route choice logic; or 2) apply the Train-Wilson origin-destination-route choice logic into a regional routing model (a Tier 2 model), input the regional routing model equilibrium waterway traffic into ORNIM, and remove ORNIM's economic equilibrium / diversion logic (versus an unscheduled closure diversion). The second step of this project is to provide proof of concept tests for the uncovered methods, and the third step is to modify the USACE planning modeling process with the selected incorporation method.




The benefits of this project include the ability to more dynamically link equilibrium waterway traffic demand forecasts with shipper specific transportation cost and time sensitivities. This project will also support more defensible investment decisions, although it is yet to be determined whether the recommendations from the planning process will be significantly different or improved.






FY06 and FY07 desgn document scope of work negotiated and executed. Code work on ORNIM conversion has begun and preliminary results expected mid-December 2006.



Contract Data:

130465, W1040




Products (Bookshelf/Toolbox):



Related Links:




Revised 23 Sep 2011

Source: Navigation Economic Technologies Program

Download the reader for PDF documents.