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In this report, the authors develop two new nonlinear spacing policies, variable time headway and variable separation error gain, designed to all but eliminate the undesirable side effect of large steady-state intervehicle spacings. This disadvantage is pronounced in heavy-duty vehicles, which require larger time headways due to their low actuation-to- weight ratio. The first policy significantly reduces the transient errors and allows for the use of much smaller spacings in autonomous platoon operation, while the second one results in smoother and more robust longitudinal control.

This paper presents a study of vehicle traction control and discusses its importance in highway automation. A robust control strategy is designed for slip control, which in turn controls the traction. It is shown how traction control can be used to satisfy different objectives of vehicle control. The importance of traction is further emphasized by comparing its performance to passive controllers in a simulation study in which an impulse-like wind disturbance is introduced. The comparative study shows that the system under traction control is stable in the presence of external disturbances...

Intelligent Transportation Systems (ITS) have generated considerable enthusiasm in the transportation community as a potential means to improve roadway safety, reduce congestion, enhance the mobility of people and goods, and reduce energy consumption and vehicle emissions. In order to estimate these potential benefits, new and improved analytical techniques and simulation models are being developed for ITS. In terms of environmental effects, the University of California, Riverside, College of Engineering-Center for Environmental Research and Technology (CE-CERT) has developed a...

Linear and nonlinear multivariate statistical analyses are applied to determine how the types of accidents that occur on heavily used freeways in Southern California are related both to the flow of traffic and to weather and ambient lighting conditions. Traffic flow is measured in terms of time series of 30-second observations from inductive loop detectors in the vicinity of the accident prior to the time of its occurrence. Results indicate that the type of collision is strongly related to median traffic speed and to temporal variations in speed in the left and interior lanes. Hit-object...