Ask the Experts–Leveraging Freight Data
Freight data at the state and regional level always surfaces as one of the biggest obstacles to good freight planning. What are some innovative things you are hearing about that are addressing this issue?
Traditional approaches to collecting freight data such as gate surveys at port facilities may not always produce meaningful data that can be used to support investment decisions. Many clients are looking for new strategies to collect better data. For example, several recent freight planning efforts have elected to make use of geographic positioning systems (GPS) data. GPS data has the advantage of being cheaper to collect than the use of trip diaries. It can be targeted to trucks operating in a specific area, and can unobtrusively collect data for a long period of time. In addition to new GPS data, commercial GPS vendors have access to historical GPS data from their trucking subscribers, which can provide much larger samples than could be collected using conventional techniques.
In the Quick Response Freight Manual (2007), written by Cambridge Systematics, the approach of collecting travel diary surveys using GPS is discussed. The manual describes how GPS receivers in trucks can trace individual truck trip activity; however, GPS-based data collection in itself cannot provide key truck trip characteristics pertaining to commodity hauled, shipment size, and activity at trip end. The maximum utility of GPS-based data collection for a travel diary survey is realized when combined with other data sources and methods of data collection. For example, combining GPS truck trip information with GIS-based land-use data can yield useful information on truck activity characteristics at trip ends.
There are a number of freight planning efforts underway that are relying on GPS data, including:
- University of Minnesota, Center for Transportation Studies: Using Archived Truck GPS Data for Freight Performance Analysis on Interstate I-94/I-90 from the Twin Cities to Chicago – This project proposes to utilize freight performance measure data and information from American Transportation Research Institute (ATRI) to study the I-94/I-90 freight corridor. Freight performance is being evaluated and analyzed to compare truck travel time with respect to duration, reliability, and seasonal variation. This data analysis process can be used for freight transportation planning and decision-making and potentially will be scalable for nationwide deployment and implementation on the country’s significant freight corridors.
- Washington State Transportation Center (TRAC): Options for Benchmarking Performance Improvements Achieved from Construction of Freight Mobility Projects – This project tested Commercial Vehicle Information System and Networks (CVISN) electronic truck transponders, which are mounted on the windshields of approximately 20,000 trucks in Washington. By using software to link the transponder reads from sites anywhere in the state, the transponder-equipped trucks become a travel-time probe fleet. The second technology tested involved placing GPS devices in trucks to collect specific truck movement data at five-second intervals. With GPS data it was possible to understand when and where the trucks being monitor experienced congestion.
- For the Federal Motor Carrier Safety Administration (FMCSA), Cambridge Systematics conducted a trucking industry perception study that documents motor carrier industry input regarding the use of roadside technologies to electronically identify commercial vehicles and the sharing of commercial driver data. This included carrier perspectives on GPS benefits, transponder benefits, cost implications of using technologies, and information sharing, and motor carrier views about automatically identifying vehicles at the roadside.
- Cambridge Systematics has proposed using GPS units and other electronic means to collect data on a number of its projects. For an update to the Southern California Council of Governments Heavy Duty Truck Model, we are prosing to use historical GPS data as an alternative to traditional truck diaries. For the National Cooperative Freight Research Program (NCFRP) Project 06, Cambridge Systematics has proposed processing historical truck GPS data from a number of urban areas to develop default values for average trip lengths, land use connections, time-of-day, and other information which would be expensive and time consuming to collect by conventional means.
Daniel F. Beagan, P.E. is a Principal of Cambridge Systematics with more than 30 years of experience in transportation, traffic analysis, and planning in the public and private sectors. His experience includes transportation forecasting, analysis, and development of mitigation for environmental impact reports (EIR) in the office, retail, residential, university, industrial, and recreational industries. He serves as a senior advisor on freight forecasting and modeling and freight data collection and analysis efforts.