Abstract-Cost is a major issue for ITS deployment in Oklahoma. We introduce a novel distributed control architecture that has totally eliminated the need for an expensive monolithic traffic management center, thereby dramatically reducing the overall system cost. Analog and digital video streams from the various metro areas are seamlessly integrated by a fault tolerant, dynamically reconfigurable peer-to-peer network of low-cost geographically distributed ITS Consoles operating under the philosophy that any console should be able to control any system resource at any time.
Practically all major metropolitan and large scale modern intelligent transportation systems have a centralized traffic management center (TMC) at their logical and functional core. The TMC provides control, coordinates system wide communications, and typically serves as a common hub from which multiple agencies plan and execute coordinated incident responses. Early in the development of the Oklahoma statewide ITS, it became clear that the costs associated with building and operating a large, centralized TMC would be prohibitive. An alternative design strategy emerged built around a distributed peer-to-peer network of low-cost ITS consoles based on desktop PC's equipped with innovative software and special hardware to support efficiently handling multiple video streams simultaneously. This has led to a geographically distributed, fault-tolerant communications and control system where the desirable functionality of a large centralized TMC is realized by a virtual TMC that enables the stakeholder agencies to remain physical located in their current facilities around the State. In this paper, we provide an overview of the system architecture as it has evolved through the first quarter of 2009 and highlight some of the recently developed system enhancements.
In an effort to monitor and alleviate roadway traffic conditions, the Oklahoma Department of Transportation (ODOT) has deployed a statewide Intelligent Transportation Systems (ITS) architecture consisting of a large number of devices, including cameras, dynamic message signs, and speed sensors along Oklahoma highways. These devices are connected throughout a private ITS fiber-optic network to controlling stations located at stakeholder agencies statewide, forming a virtual Traffic Management Center (TMC). This decentralized approach allows individual consoles on the virtual TMC to display and control reachable devices even if portions of the network become disconnected. Enabling this fault-tolerant design is a novel peer-based communications protocol. The communication system is dynamically configured and automatically resolves communications regardless of network configuration. This paper introduces this robust peer-based approach and describes its implementation within the Oklahoma virtual TMC. Results of this implementation of the system are also presented.
We introduce a simple video rate control strategy for reducing or eliminating decoder errors due to network errors and dropped packets on low bandwidth links in hetero geneous intelligent transportation system video networks. The proposed method is based on adaptively dropping frames prior to H.264 encoding. Performance of this strategy is assessed by evaluating three video quality metrics (PSNR, SSIM, and VQM) on actual traffic surveillance video that is transmitted across links with simulated network errors. We show that high spatial quality can be maintained at the expense of temporal resolution by reducing the effective frame rate as low as five frames per second, which is still sufficient for traffic network monitoring. Our solution is driven by several specialized constraints. Hence, while it is highly effective for intelligent transportation systems, this approach would not be suitable for more general video entertainment applications.Keywords-video rate control, video quality assessment, intel ligent transportation systems
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.