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Advances in information technology are making the close integration of vehicles and the infrastructure in the surface-transportation system feasible. In particular, one approach to this integration receiving significant attention and effort in the United States is referred to as vehicle-infrastructure integration (VII). While few would argue that VII possesses the potential to support applications that improve traffic safety and mobility, the level of benefits, as well as strengths/weaknesses of various design alternatives, cannot be effectively assessed without the availability of an appropriate simulation environment. The purpose of this research is to develop a simulator that can fully model the functional aspects of VII deployment. This paper identifies key requirements for development of the simulation architecture, and proposes an architecture for a VII simulation system after identifying several alternatives. The proposed architecture components include a commercial off-the-shelf (COTS) traffic sim...

The challenge of integrating multiple computer applications and systems is common in civil engineering. For example, civil engineers are working to integrate geographic information systems, database management systems, and hydraulic models for wastewater planning and design. This challenge also faces transportation engineers. Control systems, such as traffic signal systems and freeway management systems, play a central role in the intelligent transportation systems (ITS) program. While such systems provide benefit individually, their full benefit is not achieved until they are integrated regionally. Regional integration enables the systems to share information, allowing officials to manage the entire regional transportation system. Planning, designing, and developing integrated systems call for engineers to make sound computing decisions. The two critical areas in these decisions are the systems architecture and open systems design. For example, in ITS a sound regional architecture is needed to guide engineers in fitting individual systems into a regional context. In addition, individual system must possess documented, publicly available interfaces. This paper addresses these aspects of computing and provides an example of developing integrated regional ITS.

The typical infrastructure maintenance decision‐making environment involves multiple objectives and uncertainty, and is dynamic. One of the most commonly used infrastructure models is a Markov decision process (MDP). MDP models have been applied to numerous sequential decision‐making situations involving uncertainty and multiple objectives, including applications related to infrastructure problems. In this paper we explore the use of Markov models for bridge management systems. In particular, we explore two critical issues associated with the use of MDP models. The first involves state‐space explosion, one of the most common problems with MDP models. We address the issues of state‐space cardinality and present approaches for dealing with the complexity. The second issue with MDP models is the compliance with the Markovian property. With both issues we use the Virginia bridge system and data to illustrate the concepts. Our research indicates that MDPs are a powerful and useful technique for bridge manageme...