An algorithm for real-time estimation of truck traffic in multilane freeways was proposed. The algorithm used data from single loop detectors--the most widely installed surveillance technology for urban freeways in the United States. The algorithm worked for those freeway locations that have a truck-free lane and exhibit high lane-to-lane speed correlation. These conditions are met by most urban freeway locations. The algorithm produced real-time estimates of the truck traffic volumes at the location. It also can be used to produce alternative estimates of the mean effective vehicle length...
This paper describes the methodology and findings for developing improved passenger car equivalent (PCE) factors for trucks at signalized intersections on the basis of field data and simulation modeling. The Highway Capacity Manual 2010 (HCM 2010) assumes a single PCE value of 2.00 for trucks at traffic signals. The proposed truck PCE values are sensitive to the proportion of trucks, truck type, and intersection’s approach grade. It is recommended that the current HCM 2010 approach of computing the heavy vehicle and grade effects on saturation flow rates independently be replaced with a...
The Freeway Service Patrol (FSP) is an incident management program implemented by Caltrans, the California Highway Patrol and local partner agencies to quickly detect and assist disabled vehicles and reduce non-recurring congestion along the freeway during peak commute hours. The first FSP program was piloted in Los Angeles, and was later expanded to other regions by state legislation in 1991. As of June 2014, there were fourteen participating FSP Programs operating in California, deploying over 370 tow trucks and covering over 1,800 (center-line) miles of congested California freeways....
Traffic congestion will continue to worsen and likely worsen at a faster rate than ever. People throughput and freight throughput have become critical issues for California and the rest of the nation. PATH has funded a research project entitled Definition And Evaluation of Bus And Truck Automation Operations Concepts, proposed by the authors. This report summarizes the major findings of the research project. During the one-year project, we reviewed literature and developed operating concepts for both urban bus automation and inter-city truck automation. We also selected a small number of...
This report documents findings from a series of studies investigating how Intelligent Transportation Systems (ITS) could be used to improve the integration of commercial vehicle operations (CVO) with governmental services and regulations within intermodal transportation management centers. After a summary of prior project research, the report gives a review of ITS/CVO technologies. This is followed by results of interviews and focus groups that reveal that trucking companies are willing to invest and participate in projects that possess four basic characteristics: 1) modest investment, 2)...
This report focuses on the design of longitudinal control algorithms for commercial heavy vehicles (CHVs). The algorithms use nonlinear spacing policies, backstepping control design, and aggressive prediction schemes to deal with the presence of significant delays and saturations in the fuel and brake actuators. The algorithms can also deal with delays both in the presence and in the absence of intervehicle communication. A by-product on this research is the development of two software packages, Platoon-Builder and TruckVis, for simulation and animation of CHV platoons. Additionally,...
Cooperative Adaptive Cruise Control (CACC) is a driver assist technology that uses vehicle-to-vehicle wireless communication to realize faster braking and acceleration responses in following vehicles and shorter headways compared to Adaptive Cruise Control (ACC). This technology not only enhances road safety, but also offers fuel saving benefits as a result of reduced aerodynamic drag. The amount of fuel savings is dictated by the following distances and the driving speeds. So, the overarching goal of this work is to explore truck drivers’ preferences and behaviors when following in “CACC...
This report documents a review of the literature for commercial motor vehicle inspection and compliance stations and its relationship with the growth of truck travel over the next 25 years and the lack of concurrent capacity increases in staffing at such stations. Problems result in that more commercial vehicles will need to stop for inspection with longer queues at weigh stations associated with increased congestion, increased wait times, more idling trucks, and increased safety hazards. Alternatively, without stopping at inspection and compliance stations other problems will result such...
This report documents the research results of Task Order 4205 (TO4205), Fault Tolerant Lateral Control for Transient Buses and Trucks performed during 2000-2003. In this task order, we studied the procedures for designing real-time lateral control systems for automated vehicles that are not sensitive to failures of the two key components: a set of magnetometers at the front bumper and another set at the rear bumpers. This problem is important because failures related to either front or rear magnetometers may have immediate effect on the stability of the closed loop control system.
Technological innovations have recently changed many of the ways the private trucking industry operates. These changes have enabled trucking firms to monitor more closely the distribution of goods and services, improve productivity, and develop higher levels of customer satisfaction. Of these innovations, ITS related applications play an important role in creating benefits for the private sector. ITS technologies are also increasingly offering the potential to bring about change to state and national agencies charged with overseeing goods movement in trucking. Recent research has shown...
