From a single operator to an entire system, Volpe experts help transportation professionals understand how goods and people move today—and how they can move better in the future.

A single movement within a transportation network may be relatively simple. A truckload of soy beans moves from farm to biofuel refinery, for example. Or a busload of passengers travels from Boston to New York. But understanding the impacts that many individual movements have within larger transportation systems can help decision makers identify opportunities to maximize efficiency—saving time and money, and reducing emissions—and enhance safety.

U.S. DOT Volpe Center experts conduct flow analyses to provide transportation professionals with comprehensive and detailed understandings of transportation networks. These analyses are built on geographic information system (GIS) tools and methods for assigning flows on the transportation network.

Flow optimization is a kind of flow analysis that Volpe experts perform to find the best-case scenarios for specific transportation logistics situations.

The Volpe Center helps transportation professionals and transportation agencies at all levels better understand how transportation network operations can contribute to, or restrict, optimal movements. Understanding current constraints can also help identify opportunities for new roads, pipelines, and other transportation infrastructure.

Volpe Center flow analysis experts have worked with these agencies to enhance understanding of movements of freight and fuel:

• Federal Aviation Administration
• Federal Railroad Administration
• U.S. Department of Agriculture
• U.S. Department of Energy
• U.S. Navy’s Office of Naval Research

Below is a snapshot of the Volpe Center’s flow analysis capabilities and future directions, including analyses for transportation resiliency to extreme weather, energy generation, and risk-based analyses.

Inside Network Flow Analyses

Flow analyses help logistics experts and decision makers understand how materials and people move over a transportation network. Volpe Center experts apply rules to identify the route a shipment will take from origin to destination. Rules might limit, for example, the types of cargo allowed on certain modes, or apply costs to move through a segment of the network, or through a facility.

Experts may also examine logistics flows that have already happened, to understand how the flow was executed and if there were alternative routes available. And flow analyses can shed light on future scenarios where transportation patterns are not yet set, to investigate specific behaviors over the network.

To conduct network flow analyses, the Volpe Center’s GIS team leverages its expertise in these areas, from the local to global scale and across all transportation modes:

• Building custom, customizable, and flowable GIS analysis and mapping tools
• Developing comparison tools, time series animations, and maps
• Working with very large datasets, including conducting related analytics
• Combining multiple transportation networks

Flow analyses make it easier to understand the financial, time, and emissions costs of moving through intermodal facilities, entry and exit points like airports and maritime ports, and across all elements of a transportation network.

Finding the Best Transportation Flow Patterns

There are many plausible approaches to moving freight across the country. Understanding the best solution based on key priorities can help decision makers evaluate potential benefits, detriments, and opportunities of future scenarios. Flow optimization helps find the best solution or best-case scenario for a given situation.

Transportation professionals involved in logistics often need to know how current transportation networks can contribute to, or restrict, optimal freight movements. These professionals in the public and private sectors need to evaluate the impacts of historical and future transportation movements:

• How much fuel will be used for a particular movement?
• What will the emissions be?
• How much are the total shipping costs?
• Which scenarios minimize safety risks?
• What will happen to the network if new infrastructure is built?

Flow optimization builds on network flow analyses and helps transportation agencies make informed choices that minimize environmental and social risks from moving freight and fuel. Volpe has developed integrated modeling tools, such as the Freight and Fuel Transportation Optimization Tool (FTOT), to address those needs.

Watch video highlights of Volpe environmental biologist Dr. Kristin Lewis’ talk “U.S. DOT Volpe Center’s Freight/Fuel Transportation Optimization Tool: Exploring Future Energy Scenarios.”

Flow Analysis and Optimization in Action with FTOT

The Freight and Fuel Transportation Optimization Tool (FTOT) is a scenario testing model developed by Volpe experts that synthesizes various analytical approaches for flow and network analyses and optimization. It is modeling software that can be used for a variety of commodities.

Volpe experts are using FTOT to help the Federal Aviation Administration’s Office of Environment and Energy understand how much alternative jet fuel can be produced in the near term. Recent analyses have focused on the availability of commodities like residues from timber harvesting, tallow from slaughterhouses, and municipal solid waste. With FTOT, Volpe experts can use anticipated demand and projected availability of those materials in specific future years to analyze how they would flow optimally over transportation networks and how new operations may impact those networks.

For the Department of Energy’s Office of Policy, Volpe experts examine crude oil and coal scenarios. Working with data from Oak Ridge National Lab, these analyses support county-to-county flows of crude oil and coal. Volpe experts are using the FTOT network to map these data and identify the best paths for these materials—optimizing routes according to transportation costs, routing preferences, and other factors related to processing capacity and cost. 

How FTOT Works

FTOT is unique because it allows for upstream and downstream analyses that track multiple commodities within a scenario, from raw materials to various products of processing, along a supply chain. It has two core components: a GIS module and an optimization module. Its foundation is a novel multimodal network that Volpe developed from U.S. DOT datasets covering road, rail, waterways, pipelines, and intermodal facilities, such as ports where containers are moved from ship to rail.[i]

With the GIS component, users can look at how commodities and materials flow over the national transportation enterprise, using actual or hypothetical infrastructure, such as anticipated network links or potential refineries. The tool brings together parameters on costs and other factors into the national multimodal network, and then generates route options among origins and destinations.

FTOT can also encourage flow over specific infrastructure elements—for example, favoring flows over interstate highways instead of major arterial roadways, or major arterials over minor arterials. FTOT is a one-stop tool that can be leveraged, complemented, and expanded to address new analytical needs in transportation logistics.

FTOT’s foundation is a novel multimodal network that Volpe developed from U.S. DOT datasets covering road, rail, waterways, pipelines, and intermodal facilities. The tool brings together parameters on costs and other factors into the national multimodal network, and then generates route options. (Volpe image)

Future Directions

Volpe experts are exploring these applications for network flow analysis and optimization:

• Addressing energy generation and how energy flows over power grids.
• Evaluating how changes in the network (e.g., potential addition of new road, rail, or pipeline) can change optimal solutions in scenarios
• Analyzing risk and incident patterns with geospatial information
• Expanding optimization:
  • More detailed regional analyses to predict critical freight flow patterns
  • Risk-based optimization based on environmental risks, accident risk, incident patterns, and more
  • Safety analysis
  • Expanding resiliency analysis for extreme natural events