E-C158 Cover1 - Center for Transportation Analysis - Oak Ridge ...

24 Transportation Research Circular E-C158: Commodity Flow Survey Workshop
This exercise becomes more important in studies focused on specific industries or state and local
flows. No officially recognized method of assessing the accuracy of flows currently exists, but
expert practitioners generally “triangulate” between available traffic count, surveys or interviews
with select industries, and other information such as Global Positioning System data. This
process requires intuition, judgment, and skill. Frank Southworth of the Oak Ridge National
Laboratory noted that “no textbook in the world will tell you how to do this.” In the future,
research efforts might document existing methods or develop new ones to assist with this
process.
• Weaknesses in data. Workshop panelists and participants acknowledged continuing
weaknesses in the CFS data that are important to consider in future versions. Two broadly cited
weaknesses include
― The inability of the current CFS to properly account or separate emerging
renewable energy commodities, including biofuels; and
― The inability of the CFS to accurately trace the movement of intermodal
commodities, especially for domestic flows of international trade.
To address the first area, developing a way to separate out commodities of emerging
national significance could substantially benefit stakeholders. While some improvement has been
made to more fully track multimodal commodities through the supply chain, the second area
could be improved through additional efforts to use telemetric data sources to follow cargo
across modes. Other improvement efforts might seek ways to more fully leverage the knowledge
and data of 3PLs and other transportation agents which arrange most multimodal freight moves.
Discovery and Rediscovery
Workshop panelists and participants discussed in detail many of the questions they routinely
seek to answer with the CFS data. During the course of these conversations the participants cited
the desire for greater access to core CFS data and the establishment (or dissemination) of
methods to extend the usefulness of the CFS. Based on panelist input, the primary discovery
activities of the user community are data mining, including access to microdata, and the
development of methods to add value to the CFS through linkages to other data sets. In some
cases, user questions have already been solved through existing research. In these situations,
better education and dissemination could help the user community rediscover the methods
pioneered by others.
• Data mining and microdata. Panelists and participants emphasized that the existing
CFS data set can be a rich source if properly “mined” through queries of the microdata and other
activities. For example, if the geographic detail of the CFS were suppressed, researchers could
use the most detailed commodity flow information to develop other useful and broadly
applicable tools such as average mileages by mode and commodity, or profile of industry type.
Because the CFS data—at a granular level of geography—contain confidential establishment
information, access to the microdata has been restricted. To help meet the demand for data
mining and microdata access, the Census Bureau is establishing 11 regional centers for
microdata analysis. Researchers gain access to the microdata through the development of
research proposals submitted to Census.