This chapter presents the results of experiments on coordinated automatic longitudinal control of a platoon of three Class 8 tractor-trailer trucks, using 5.9 GHz DSRC with 100 ms update intervals for coordination. The trucks were tested not only in constant-speed cruising conditions, but also through acceleration and deceleration profiles, up and down grades, and in platoon join and split maneuvers using the DSRC coordination. These tests showed good vehicle following accuracy, ride quality and platoon stability. The desired gaps between the trucks were varied between 10 and 4 m to...
Quantifying the effect of Cooperative Adaptive Cruise Control (CACC) on traffic mobility and vehicle fuel consumption has been a challenge because it requires a modeling framework that depicts the interactions among manually driven vehicles and CACC vehicles in the complex multilane traffic stream. This study adopted a state-of-the-art traffic flow modeling framework to explore the impacts of CACC on vehicle fuel efficiency in mixed traffic. The analyses at a freeway merge bottleneck indicated that the CACC string operation resulted in a maximum of 20% reduction in energy consumption...
Cooperative adaptive cruise control (CACC) vehicle string operations have the potential to improve significantly the mobility and energy consumption performance of congested freeway corridors. This study examines the impact of CACC string operations on vehicle speed and fuel economy on the 13-mi SR-99 corridor, near Sacramento, CA. It extends the existing body of knowledge by performing a multi-scenario simulation analysis of the freeway corridor. A simulation study evaluated the performance of the corridor under various CACC market penetration scenarios and traffic demand inputs. The CACC...
The aviation sector in California is facing increased pressure to reduce its carbon footprint, leading to a growing interest in alternative fuel aviation (AFA) technologies such as sustainable aviation fuel (SAF), as well as electric- and hydrogen- powered aircraft. The report develops a California Aviation Energy Model (CAVEM), examining various AFA technologies and analyzing possible policy options. The analysis emphasizes the importance of SAF in the short term, with projections indicating sufficient supply for intrastate flights and capped vegetable oil-based fuel consumption. Long-...
Reducing fuel consumption is a major goal for the aviation community due to environmental concern and fuel price uncertainty. The Federal Aviation Administration (FAA) is currently developing and implementing Air Traffic Management (ATM) technologies to ensure reliable operational performance that is robust to delays caused by congestion and weather. These technologies will reduce planned and unexpected airborne delays; as such they will reduce the airline practice of schedule padding, or contingency planning for excess fuel and time consumption on a give route, as well as airborne and...
This dissertation presents a hierarchical, hybrid point of view to the control of large-scale systems. The analysis is based on a new hybrid dynamical system formulation that allows for the modelling of large scale systems in a modular fashion. Three problems are addressed: controller design, closed loop performance verification and the extension of system autonomy. A control scheme based on semi-autonomous agent operation is first proposed. An algorithm, using ideas from game theory, is presented to produce continuous controllers for hierarchical, hybrid designs. A discussion of design...
Signal equipment upgrades (e.g., multiple timing plan capability and/or signal interconnection) are commonly used to improve the quality of traffic flow in urban arterials and networks. These signal control improvements generally result in considerable delay, stops and fuel savings but the benefits vary widely on different networks. Procedures are needed to provide guidance on the benefits likely to be achieved from improving signal hardware. This report discusses the major factors that influence signal equipment performance and presents the findings of the assessment of the impacts from...
The Fuel-Efficient Traffic Signal Management (FETSIM) Program was initiated in 1982 to help local agencies retime their traffic signals to reduce stops, delays, and fuel consumption. This report presents the results of the fourth and fifth grant cycles of the FETSIM Program. During the two grant cycles, local agency staff and their consultants were provided training, technical assistance and funding necessary to optimize the timing of their signal systems and to put the new timing plans into operation. In the 1986 grant cycle, thirty-one local agencies retimed 1169 signals at a total cost...
Need to develop theory, tools, and methods that allow for self-consistent and transparent comparisons of promising alternative energy and vehicle pathways (hydrogen, biofuels, electricity, and fossil fuels). Also, to inform the public debate and to assist our public and private sponsors on sustainable transportation alternatives.
This study aims to improve operational performance of a multiple airport region (MAR) by analyzing interdependent capacity scenarios of that MAR airports and redistributing airport traffic to make more efficient use of the available capacity. We propose to shift flights between MAR airports in order to reduce flight delays. Both the deterministic and stochastic versions of a flight shift model are formulated as a mixed-integer linear program (MILP). The proposed methodology is applied to New York MAR, which includes five airports, using data for the year 2015. The deterministic model is...
