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In this report, we extend our previous work within MOU 372 on modeling and longitudinal speed control design for heavy commercial vehicles equipped with variable compression braking mechanisms. Previously, we developed a detailed crankangle based simulation model for a six cylinder, 350 hp diesel engine with a continuously varying compression brake that is capable of describing the intrinsic interactions between individual cylinder intake and exhaust processes, turbocharger dynamics during combustion and braking modes, and the transition between those modes. Moreover, for control design...

This report investigates how Caltrans may incorporate third-party vendor data into its established system for performance measurement to improve accuracy of vehicle hours of delay (VHD) estimates and to enable smarter deployment of point-based sensors, such as loops. Methods are evaluated to project data from multiple sources, including multiple vendors and internal data feeds, onto the same domain of analysis so as to compute performance metrics with high fidelity. The recommended VHD estimation method depends on the infrastructure type and the data available. Overall a hybrid approach...

In this paper, the authors describe the successful combination of a low- level, vision-based surveillance system with a high-level, symbolic reasoner based on dynamic belief networks. This prototype system provides robust, high-level information about traffic scenes. The machine vision component of the system employs a correlation-based tracker and a physical motion model using a Kalman filter to extract vehicle trajectories over a sequence of traffic scene images. The symbolic reasoning component uses a dynamic belief network to make inferences about traffic events. In this paper, the...

The Wireless Token Ring Protocol (WTRP) is a medium access control protocol for wireless networks in Intelligent Transportation Systems. It supports quality of service in terms of bounded latency and reserved bandwidth. WTRP is efficient in the sense that it reduces the number of retransmissions due to collisions. It is fair in the sense that each station takes a turn to transmit and is forced to give up the right to transmit after transmitting for a specified amount of time. It is a distributed protocol that supports many topologies since not all stations need to be connected to each...