Bruce E Peterson

INTERMODAL AND INTERNATIONAL FREIGHT NETWORK MODELING

The authors describe the development and application of a single, integrated digital representation of a multimodal and transcontinental freight transportation network. The network was constructed to support the simulation of some five million origin to destination freight shipments reported as part of the 1997 United States Commodity Flow Survey. The paper focuses on the routing of the tens of thousands of intermodal freight movements reported in this survey. Routings involve different combinations of truck, rail and water transportation. Geographic information systems (GIS) technology was invaluable in the cost-effective construction and maintenance of this network and in the subsequent validation of mode sequences and route selections. However, computationally efficient routing of intermodal freight shipments was found to be most efficiently accomplished outside the GIS. Selection of appropriate intermodal routes required procedures for linking freight origins and destinations to the transportation network, procedures for modeling intermodal terminal transfers and inter-carrier interlining practices, and a procedure for generating multimodal impedance functions to reflect the relative costs of alternative, survey reported mode sequences.

Development of a Regional Routing Model for Strategic Waterway Analysis

The Navigation Economics Technologies suite of models is being developed by the U.S. Army Corps of Engineers to bring new analytic tools to the process of evaluating and planning navigation investments. A hierarchical and potentially iterative approach consisting of three levels, or tiers, has been proposed, one that moves from a broad regional and global geography in Tier 1, down to a detailed, project- and facility-specific level of detail in Tier 3. This paper describes the construction of a commodity flows database to support Tier-2 modeling. Called the regional routing model, it takes spatial disaggregations of broad regional forecasts of commodity flows to a point at which they can be assigned to specific modes and routes over the U.S. transportation network. The paper describes the model structure and how it is being tied closely to a multisource database constructed to support base year model calibration. A goal for the model is to be able to measure the effects on flows and transportation costs of changes to either the capacity of the transportation network or to the volume of goods produced and consumed. Some preliminary results are shown.

Analysis of Fuel Ethanol Transportation Activity and Potential Distribution Constraints

An analysis is provided of fuel ethanol transportation activity and potential distribution constraints if the total 36 billion gal of renewable fuel use by 2022 is mandated by the U.S. Environmental Protection Agency (EPA) under the Energy Independence and Security Act of 2007. Ethanol transport by domestic truck, marine, and rail distribution systems from ethanol refineries to blending terminals is estimated with the Oak Ridge National Laboratorys North American infrastructure network model. Most supply and demand data provided by EPA were geocoded, and the transportation infrastructure network was updated through use of available commercial sources. The percentage increases in ton-mile movements by rail, waterways, and highways in 2022 are estimated to be 2.8%, 0.6%, and 0.13%, respectively, compared with the corresponding 2005 total domestic flows by various modes. Overall, a significantly higher level of future ethanol demand would have a minimal impact on the transportation infrastructure. However, there will be spatial impacts, and a significant level of investment will be needed because of a considerable increase in rail traffic from refineries to ethanol distribution terminals.

Routing Hazardous Materials around the District of Columbia Area

The recent hazardous material (hazmat) shipment ban in Washington, D.C., has led to debates, legal challenges, and considerations by other major cities to pursue similar actions. This article presents a methodology for evaluating hazmat shipment routing options on railroad networks under situations such as the shipment ban. A case study involving three alternatives is presented. Population and other vulnerable people within a 0.8 km (or 0.5 mile) radius buffer zone along the rail line are used to evaluate the potential risk associated with ultra-hazardous material (i.e., explosives, flammable gasses, poisonous gasses, and poisonous materials) shipments. Based on this study, it is concluded that moderate increases in ton-km, and subsequently time in transit, will be a result from the rerouting. On the other hand, the overall population at risk will see a reduction. The population-at-risk burden, however, is simply shifted from one location to other locations. This article also identifies areas for potential follow-up efforts.

Geospatial Products and Techniques at the Center for Transportation Analysis

ABSTRACT This paper highlights geospatial science-related innovations and developments conducted by the Center for Transportation Analysis (CTA) at the Oak Ridge National Laboratory. CTA researchers have been developing integrated inter-modal transportation solutions through innovative and cost-effective research and development for many years. Specifically, this paper profiles CTA-developed Geographic Information System (GIS) products that are publicly available. Examples of these GIS-related products include: the CTA Transportation Networks; GeoFreight system; and the Web-based Multi-Modal Routing Analysis System. In addition, an application on assessment of railroad hazmat routing alternatives is also discussed.