Upcoming Events

TRB 93rd Annual Meeting Presentations

The following freight-related projects will be presented at the upcoming TRB 93rd Annual Meeting in Washington D.C.

Validating Truck Route Enumeration Algorithms Using GPS Data
Pedro Camargo and Andre Tok
Session 520: Current Research in Freight Transportation and Logistics Planning and Operations, Part 1 (Part 2, Session 568)
Tuesday, January 14, 2014 8:30AM - 10:15AM
Truck assignment is performed on a subset of the roadway network, as truck traffic is restricted due to geometric, pavement, urban or environmental conditions. Therefore the path building for the assignment procedure is restricted by the roadways that allow truck traffic. When considering route choice methods for truck assignment, the first problem to be tackled is the route enumeration procedure and, as it would be expected, such procedure would have to be validated before those routes can be used in a choice model. In the state of California and in most of the United States, trucks have to stay in designated truck routes as long as possible, and only leave such routes to complete the first or last mile of their trip. Data to validate truck route enumeration has relied historically on counts and surveys, but these procedures take time and require monetary resources. The recent evolution in technology made it possible for commercial vehicles to use GPS tracking devices, and the availability of GPS data for truck routes in large scale opened the possibility of validating the results generated by route enumeration algorithms.

Exploratory Use of Raster Images as Data Source for Freight Modeling
Pedro Camargo, Michael McNally, Stephen Ritchie
Session 791: Advances in Freight Data Collection and Application
Wednesday, January 15, 2014 10:15AM - 12:00PM
When working with freight planning, particularly commodity modeling, it is frequently a daunting task to find data sources, especially data disaggregate to county or less than county levels. If one considers the case of agricultural commodities, information availability is further reduced since agricultural census data collection is infrequent and is not complete in terms of crops covered, nor does data exist below the county level in terms of geographical aggregation. Additionally, data sources such as the Freight Analysis Framework (1), FAF, often present annual data. Since transportation models are usually developed for peak periods and/or typical days, the traditional assumption of flat peak factors are not consistent with the fact that agricultural commodities are very seasonal and with seasonal patterns that vary from State to State and within a single State. It is in this setting that we tested the use of raster images provided by the USDA in two different analyses: FAF disaggregation and seasonality analysis. We present results that include models for FAF disaggregation that greatly outperform the best models currently available in the literature and a full procedure for computing agricultural seasonality for any geographical aggregation necessary.

Integration of Weigh-in-Motion and Inductive Signature Technology for Advanced Truck Monitoring
Sarah Hernandez, Andre Tok, Stephen Ritchie
Session 381: Innovations in Vehicle Detection
Monday, January 13, 2014 2:00PM - 3:45PM
Trucks have a significant impact on infrastructure, traffic congestion, energy consumption, pollution and quality of life. To better understand truck characteristics, comprehensive high resolution truck data is needed. Higher quality truck data can enable more accurate estimates of GHGs and emissions, allow for better management of infrastructure, provide insight to truck travel behavior, and enhance freight forecasting. Currently, truck traffic data is collected through limited means and with limited detail. Agencies can obtain or estimate truck travel statistics from surveys, inductive loop detectors (ILD) and weigh-in-motion (WIM) stations, or from manual counts, each of which have various limitations. Of these sources, WIM and ILD seem to be the most promising tools for capturing detailed truck information. Axle spacing and weight from existing WIM devices and unique inductive signatures indicative of body type from ILDs equipped with high sampling rate detector cards are complementary data sources that can be integrated to provide a synergistic resource that otherwise does not exist in practice, a resource that is able to overcome the drawbacks of the traditional truck data collection methods by providing data that is detailed, link specific, temporally continuous, up-to-date, and representative of the full truck population. This integrated data resource lends itself very readily toward detailed truck body classification which is presented as a case study. This body classification model is able to predict 35 different trailer body types for FHWA class 9 semi-tractors, achieving an 80 percent correct classification rate. In addition to the body classification model, the large data set resulting from the case study is itself a valuable and novel resource for truck studies.

Determinants of Air Cargo Traffic in California
Paulos Lakew and Andre Tok
Air Cargo Subcommittee, AV040(1)
Wednesday, January 15, 2014 10:15AM - 12:00PM
Studies on the impact of air cargo traffic on regional economies have been gaining traction in recent years. However, the slow growth of air cargo traffic at California’s airports has raised more pressing questions amongst airport planners and policy makers regarding the determinants of air cargo traffic itself. Specifically, it would be useful to know how the total outbound and inbound cargo traffic at airports depends on the surrounding metropolitan characteristics. Accordingly, this study aims to estimate the socioeconomic determinants of air cargo tonnage at airports in California. We construct a 7-year panel (2003-2009) using quarterly employment, population, and traffic data of metro areas in the state. Our results confirm our expectation that the shares of manufacturing and government-related employment have a strong impact on outbound air cargo traffic. Outbound cargo traffic is also found to be proportionate with city size while the corresponding inbound traffic increases less than proportionally to population. Income and service-related jobs are found to play a substantial role in determining both outbound and inbound air cargo movement. We also provide point estimates for the traffic diversion between airports, showing that up to 78% of air cargo traffic is diverted away from a small airport located within 100 miles of a large one. Some of our counterintuitive results regarding metropolitan unemployment rate and construction employment raise interesting questions for new research avenues.

Alternative Method to Estimate Balancing Factors for Disaggregation of Origin-Destination Matrices
Neda Masoud, Fatemeh Ranaiefar, Michael McNally, Daniel Rodriguez-Roman, Stephen Ritchie
Session 520: Current Research in Freight Transportation and Logistics Planning and Operations, Part 1 (Part 2, Session 568)
Tuesday, January 14, 2014 8:30AM - 10:15AM
The solution algorithms for the family of flow distribution problems, which include (1) the trip distribution problem of travel forecasting, (2) the OD estimation from link counts problem, and (3) the trip matrix disaggregation problem, are usually based on the Maximum Entropy (ME) principle. ME-based optimization problems are hard to solve directly by optimization techniques due to the complexity of the objective function. Thus, in practice, iterative procedures are used to find approximate solutions. These procedures, however, cannot be easily applied if additional constraints are needed to be included in the problem. In this paper a new approach for balancing trip matrices with application in trip matrix disaggregation is introduced. The concept of generating the most similar distribution (MSD) instead of the Most Probable Distribution of Maximum Entropy principle is the basis of this approach. The goal of MSD is to minimize the deviation from the initial trip distribution, while satisfying additional constraints. This concept can be formulated in different ways. Two MSD-based objective functions have been introduced in this paper to replace the ME-based objective function. One is the Sum of Squared Deviations MSD (SSD-MSD), and the other is Minimax-MSD. While SSD-MSD puts more emphasis on maintaining the base year trip shares as a whole, Minimax-MSD puts more emphasis on maintaining the share of each individual element in the trip table. The main advantage of replacing the entropy-based objective functions with any of these functions is that the resulting problems can include additional constraints and still be readily solved by standard optimization engines. In addition, these objective functions could produce more meaningful results than entropy-based functions in regional transportation planning studies, as shown in the case study and some of the examples. Several examples and a case study of the California Statewide Freight Forecasting Model (CSFFM) are presented to demonstrate the merits of using MSD-based formulations.

A Structural Direct Demand Model for Inter-regional Commodity Flow Forecasting
Fatemeh Ranaiefar, Joseph Chow, Michael McNally, Stephen Ritchie
Session 520: Current Research in Freight Transportation and Logistics Planning and Operations, Part 1 (Part 2, Session 568)
Tuesday, January 14, 2014 8:30AM - 10:15AM
A new framework for inter-regional commodity flow forecasting is presented to improve estimates of freight demand for inter-regional and statewide transportation models. The Structural Equations for Multi-Commodity OD Distribution (SEMCOD) model is based on simultaneous direct demand equations with structural relationships between dependent and independent variables of the model. SEMCOD is a flexible model that integrates the generation and distribution steps in conventional four-step demand models. This integration provides consistent estimates for elasticity analysis of effective factors for freight flows at the OD level and for productions and attractions at the zone level. Also, the model is sensitive to policies that increase or decrease generalized transportation cost, not only for flow distribution but also by measuring the change in marginal production and attraction of each zone. Unlike gravity-type models, this framework provides the opportunity to identify homogenous clusters of ODs and to more accurately estimate parameters for each cluster. The proposed model is estimated using the Freight Analysis Framework (FAF3) and other publicly available data sources for 15 commodity groups. Elasticity of different factors on production, attraction and flow of different commodity groups with respect to industry specific employment, population, industrial GDP, variables related to consumption and production of energy and land use variables, are studied. Considering cross relationships between supply chains of different commodity groups in the model significantly improved the fitness of the model. The fitness measures confirm satisfactory performance of the model.

CSFFM Project Delivery

Stay tuned for the CSFFM 2010 project delivery.

Past Events

TRB SHRP 2 Symposium Presentation

Pedro Camargo presented his paper on the use of raster images in transportation modeling at the Transportation Research Board SHRP 2 Symposium. The TRB, Second Strategic Highway Research Program conducted its second symposium centered on innovative freight demand modeling and data on October 21 & 22, 2013. Click here for more information

Combined CSFFM/CSTDM Technical Meeting and Peer Advisory Committee Meeting

ITS-Irvine | July 2012

1. Review of both overall and detailed progress of CSFFM
2. Technical issues related to the integration of CSFFM and CSTDM
3. Development of the integration plan
4. A summary of the meeting will be documented on this portal

Anticipated attendees:
1. Caltrans (Office of Travel Forecasting and Analysis, Division of Transportation System Information)
2. UCI ITS Team Members
3. Cambridge Systematics

- Ron West, Principal Investigator (CSTDM Update)
4. Technical Peer Advisory Committee:
- Scott Drum, Manager, Research and Market Information (Port of Portland)
- Anne Goodchild, Assistant Professor (University of Washington)
- J. Douglus Hunt, Professor (HBA Specto & University of Calgary)
- Ram Pendyala, Professor (Arizona State University)
- William (Bill) Rogers, Senior Program Officer (TRB)
- Eric Shen, Director of Transportation Planning (Port of Long Beach)
- Frank Southworth, Principal Research Scientist (Georgia Institute of Technology)

ITS Freight Team at the Port of Long Beach

The Port of Long Beach Division of Transportation Planning provided a tour specially for the EngrCEE 298 Freight Transport class and Freight Team on May 22.

Photo Credit: Jinheoun Choid, UCI ITS

UCI ITS went to the UCTC Student Conference at UC Davis

The UC Davis Sustainable Transportation Center hosted the University of California Transportation Center (UCTC) Student Conference on April 20, 2012. UC Irvine's ITS students presented their research findings to other students in various areas of transportation studies.

UCI ITS students at the UCTC Conference, UC Davis, April 2012

UCI ITS at the Transportation Research Board (TRB) 91st Annual Meeting

The TRB 91st Annual Meeting was held in Washington, D.C., January 22-26, 2012, at the Washington Marriott Wardman Park, Omni Shoreham, and Washington Hilton hotels. ITS faculty and students were among the 11,000 plus transportation professionals from around the globe attending the information-packed meeting programs.

ITS at the TRB 91st Annual Meeting, Washington, D.C, January 2012

Freight Project Kick-off Meeting at Caltrans

The California Statewide Freight Model (CSFM) Kick-off Meeting was held at the Caltrans Headquarters on January 4, 2012. Participants of the meeting included project members from Caltrans, UC Irvine, and ARB. The CSFM background and scope were discussed before addressing the basic model and enhancements.