Recommended CitationKrogmeier, J. V., and D. M. Bullock. Statewide Wireless Communications Project, Volume 2: Inductive Loop Detection of Bicycles and Inductive Loop Signature Processing for Travel Time Estimation. Publication FHWA/IN/JTRP-2005/13-2. Joint Transportation Research Program, Indiana Department of Transportation and Purdue University, West Lafayette, Indiana, 2008. doi: 10.5703/1288284314219.
The Statewide Wireless Communications Project was an umbrella project intended to support various INDOT activities in the area of wireless communications. As these activities were conducted independently the report for the project is organized into three volumes. Volume 1 contains the results of satellite and cellular communications field testing undertaken in support of INDOT’s SiteManager application. Volume 1 also contains the results of an evaluation of spread spectrum radios for long-range communications. Volume 2 contains the results of detection zone evaluation for loop detection of bicycles and the results of testing algorithms for travel time estimation using vehicle re-identification based on inductive and micro-loop signatures. Finally, Volume 3 contains the results of preliminary testing of a vehicle-infrastructure integration application in road condition monitoring. In Volume 1 we found that SiteManager could not be adequately run over a satellite link because the long round trip delay of the communication link negatively interacted with SiteManager’s internal client-server communications protocol to severely reduce overall throughput. A solution to the problem was to use terminal emulation in the field with the client software running on a computer connected to the server via a high bandwidth, low delay link. The downside to the terminal emulation approach is that it requires that the field engineer have a communication link wherever the application is run. In Volume 1 we also found that current generation spread spectrum radio ranges in Indiana topography with antenna heights corresponding to signal arm mounting were on the order of 3 miles. This was too short by a factor of 3 to support a multihop network for traffic signal control and telemetry. In Volume 2 we developed a numerical technique for mapping the bicycle detection zones of loop detectors. A number of recommendations were made concerning loop geometry, depth, detector sensitivity, and pavement markings for purposes of improving bicycle detection. We also developed algorithms for travel time estimation based on vehicle signatures captured from commercially available inductive and micro-loop detector cards. The travel time estimation algorithms were field tested and show promise. In Volume 3 a prototype road condition monitoring system was built upon a passenger van platform and preliminary field testing and data analysis was done. Algorithms were developed to address positional uncertainties present in GPS measurements in order to allow the averaging of data taken in multiple independent runs. The results were also field tested using INDOT’s Laser Profiling vehicle
satellite communications, TCP/IP, spread spectrum radios, inductive and micro-loop detection, vehicle-infrastructure integration, SPR-2852
Joint Transportation Research Program
West Lafayette, IN
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