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Automobile manufacturers have introduced plug-in hybrid electric vehicles (PHEVs) to reduce fossil fuel consumption. This paper details three optimization strategies that can be used to minimize the energy consumption of PHEVs further through an information exchange between PHEVs and infrastructure agents supported by connected vehicle technology (CVT). An earlier study focused on a freeway scenario. The study reported here developed strategies for an urban scenario with frequent stop-and-go conditions. Three strategies were considered on the basis of different types of information availability with the use of CVT. Only signal timing information was available in Strategy 1; only headway information was available in Strategy 2; and both signal timing and headway information were available in Strategy 3. The performance of PHEVs that received no real-time information was used as the base case for Strategies 1, 2, and 3 to evaluate each strategy. The optimization strategies resulted in energy consumption savings that ranged from 60% to 76%. An analysis, with various levels of penetration of CVT-supported PHEVs in traffic, was conducted to demonstrate the impact of these optimization strategies with their increased market share. For a case study network, a linear trend was found between energy savings and the penetration rate of CVT-supported PHEVs. Strategy 3, in which signal timing and headway data were provided to CVT-supported PHEVs, resulted in about 31% to 35% energy savings, with a 30% penetration of CVT-supported PHEVs at the peak hour volume.

Given the anticipated increases in highway traffic, the scale and complexity of the traffic infrastructure will continue to grow progressively in time and in distributed geographical areas. To assure transportation efficiency, safety, and security in the presence of such growth, it is critical to identify an infrastructure development methodology that can adapt to expansions while assuring reliable operation for both centralized monitoring and distributed management. In this paper, a wireless sensor network design methodology is presented, aimed at providing effective distributed surveillance, anomaly detection, and coordinated response. The proposed methodology integrates state-of-the-art traffic sensors, with flexibly programmable controller devices that can integrate with the available traffic control equipments.The system methodology provides a paradigm in which sensors and controllers can be progressively incorporated and programmed to autonomously coordinate with peer sensors and a hierarchy of controllers to detect, notify, and react to anomalous events. Since the system can tolerate failure of parts of the system, as the network connectivity continues to increase, the proposed sensor network will have positive implications on evacuation plans during natural disasters or terrorist attacks. To illustrate the design methodology and usage, a simulated system along a freeway corridor in South Carolina was constructed in an integrated microscopic traffic and wireless sensor network simulation platform, in which distributed incident detection and response functions were implemented. The test results, including detection and false alarm rates and wireless communication latencies, are analyzed to identify insights of the system's operation and potential enhancement strategies. INTRODUCTIONEnsuring the efficiency of the nation's highway transportation infrastructure in the coming decades without costly expansion is a challenge of importance. Increasing population, vehicles, and the excessive traffic induced by urban sprawl has overburdened the existing highway system. Recent threats of terrorism also revealed the highway system's many vulnerabilities and the pressing needs for solutions that jointly assure transportation capability, safety, and security.Many cites around the world have been using a variety of technologies and systems to better manage and control their surface transportation network under the intelligent transportation systems (ITS) umbrella. As is commonly accepted by the transportation communities, widely and densely deployed traffic sensors for highway traffic surveillance and control are the key component for a majority of ITS functions, such as traveler information, real time traffic management, incident management, natural and human hazard evacuation.Currently, the majority of roadside sensors are connected by copper wires, fiber-optic cables, or a cellular wireless network to a centralized control center. At the center, human operators are responsible for continuously monitoring and analyzing...

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