<?xml version="1.0" encoding="utf-8"?><rss version="2.0" xmlns:atom="http://www.w3.org/2005/Atom"><channel><title>TRB Publications Index</title><link>http://pubsindex.trb.org/</link><atom:link href="http://pubsindex.trb.org/common/TRIS Suite/feeds/rss.aspx?tc=NN%3ASfrwbfr" rel="self" type="application/rss+xml" /><description></description><language>en-us</language><copyright>Copyright © 2015. National Academy of Sciences. All rights reserved.</copyright><docs>http://blogs.law.harvard.edu/tech/rss</docs><managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor><webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster><image><title>TRB Publications Index</title><url>http://pubsindex.trb.org/Images/PageHeader-wTitle.png</url><link>http://pubsindex.trb.org/</link></image><item><title>A Reliable Low-Cost Interlocking System for Regional Railway Lines</title><link>http://pubsindex.trb.org/view/2407072</link><description><![CDATA[This article deals with the topic of remote control systems for railway transport with a focus on increasing the safety of transport on regional rail lines and increasing the reliability of the RadioBlock interlocking system to ensure the sustainability of operations on lines with lower traffic volume. The paper provides a general explanation of traffic management through control centres, while also considering the efficiency aspects of remote control, which allows for more efficient operation on lines, which has a direct impact on the maintenance of traffic and services, especially on regional lines. As well, the analytical part of the article is focussed on the RadioBlock interlocking system, including an explanation of its operating procedures and technical shortcomings. The next section presents the characteristics of using radio frequency technology in rail transport. This is followed by a proposal for upgrading the RadioBlock system by implementing radio frequency technology, and a description of the traffic management according to the proposal is also given. The characteristics of the proposed solution are then presented, which enables the safety of train movements without the need to install a costly train protection system, including the acquisition of expensive equipment. There is also a summary of the results obtained and a reflection on the future direction of research in the field of alternative interlocking systems.]]></description><pubDate>Wed, 20 Nov 2024 13:08:58 GMT</pubDate><guid>http://pubsindex.trb.org/view/2407072</guid></item><item><title>Guidebook for Detecting and Mitigating Low-Level DC Leakage and Fault Currents in Transit Systems</title><link>http://pubsindex.trb.org/view/1695364</link><description><![CDATA[Improving the reliability of railway electric systems and preventing electrical outages due to insulator flashover and insulation failure is difficult because of aging infrastructure and the lack of continuous monitoring of the state of the systems.  This report documents low-level leakage current detection methods using two approaches. The first approach involves injecting a high frequency signal into a segment of the power line nonintrusively and determining the high frequency impedance of the selected line segment. Segmentation of the line is achieved by applying a virtual blocker at each end of the chosen segment. The high frequency impedance of that segment is thus linked to the condition of the cable and the level of the leakage current in the segment. The second approach measures the radio frequency (RF) emissions from the power network and relates the condition of the network to the frequency content of those emissions. This guidebook provides specifications for the sensors for the two approaches as well as outlines their capabilities and appropriate operating conditions. The sensors developed can be classified into two categories: (1) nonintrusive injection-based and (2) RF emission-based sensors. The frequency, voltage, and current limitations are specified for the injection-based sensors. The data processing and linkage to failures along with the frequency of operation are provided for the RF emission-based sensors.]]></description><pubDate>Wed, 08 Apr 2020 13:47:09 GMT</pubDate><guid>http://pubsindex.trb.org/view/1695364</guid></item><item><title>A Low-Cost Real-World Planning Strategy for Deploying a Dedicated Short-Range Communications Roadside Unit on a Highway Off-Ramp</title><link>http://pubsindex.trb.org/view/1579164</link><description><![CDATA[The deployment of dedicated short-range communications (DSRC) roadside units (RSUs) allows a connected or automated vehicle to acquire information from the surrounding environment, such as a traffic light’s signal phase and timing, using vehicle-to-infrastructure communication. Several scholarly papers exist on planning strategies for DSRC RSU deployments using simulation without accounting for wireless communication constraints and environmental changes. This paper proposes an empirical-based planning strategy for a highway off-ramp in a real-world environment. The research goal focuses on developing a low-cost and structured deployment plan for DSRC RSUs with the following objectives: use free planning tools; apply the deployment strategy in a real-world environment; utilize publicly available DSRC RSU data measurements; and leverage existing intelligent transportation systems infrastructure when possible. The proposed planning strategy includes three steps: (1) conduct a virtual site survey, (2) gather baseline performance data for the DSRC RSU equipment, and (3) generate a predictive radio frequency signal. The planning strategy was successfully applied on a highway off-ramp at exit 19A of the Capital Beltway, which encircles Washington, DC.]]></description><pubDate>Thu, 17 Jan 2019 15:19:18 GMT</pubDate><guid>http://pubsindex.trb.org/view/1579164</guid></item><item><title>Tire Pressure Monitoring System Sensor Radio Frequency Measurements for Privacy Concerns</title><link>http://pubsindex.trb.org/view/1437308</link><description><![CDATA[Since the National Highway Traffic Safety Administration mandated the incorporation of tire pressure monitoring systems (TPMSs) in all newly produced passenger vehicles, most vehicle manufacturers have adopted direct pressure measurement. Direct TPMS sensors embedded in each tire require a wireless radio frequency (RF) communications link that broadcasts tire status to the vehicle once per minute from each tire when at speed. Each TPMS message communicates benign information that includes pressure and temperature as well as a static unique identifier that may be exploited, which raises concerns about privacy and spoofing. To focus on concerns related to the TPMS-RF interface, vehicle motion simulations were integrated with live propagation modeling measurements from three classes of passenger vehicles: subcompact car, full-size sedan, and full-size pickup. The RF link and channel models for this TPMS interface with the vehicle resulted in surprisingly long ranges away from the vehicle for the radiation of the unique identifiers. A TPMS sensor redesign could use the proposed RF channel propagation measurements to change the directions of signal propagation while reducing battery consumption by the TPMS sensor (which is affected primarily by RF transmission).]]></description><pubDate>Thu, 29 Dec 2016 15:53:03 GMT</pubDate><guid>http://pubsindex.trb.org/view/1437308</guid></item><item><title>Utilization of Radio-Frequency Identification Tags for Transportation Infrastructure Management: Tracking Engineered-to-Order Elements and Materials Throughout Their Life-Cycles</title><link>http://pubsindex.trb.org/view/802397</link><description><![CDATA[Information flow related to materials and components used in transportation infrastructure systems and their supply chains are plagued with inefficiencies; translating into a variety of problems throughout the life-cycle of these systems. Examples of problems include inadequate or late deliveries to construction sites and components installed at wrong locations at construction sites. High fragmentation in the transportation infrastructure supply-chains further complicates the flow of information. Current manual and labor-intensive methods of tracking components and materials and information associated with them are inefficient resulting in incomplete/inaccurate information or unavailability of information during the life cycle of infrastructure. Radio Frequency Identification (RFID) Tags provide a means to track components from longer distances, store information on the components and enable multiple parties access this information throughout the life-cycle of those components. This paper provides a vision of having intelligent transportation infrastructure components and materials, which know their identities, locations and history, and communicate this information to their environments as a way to address the issues associated with poor tracking and managing of information associated with these components. We specifically propose streamlining information flow through a supply chain by utilizing RFID. To explore the technical feasibility of having intelligent components, a requirements analysis was conducted and based on that, a set of field tests were performed.  These experiments demonstrated that it is technically feasible to have intelligent components for transportation infrastructure systems and to automatically collect status information within a supply chain.]]></description><pubDate>Thu, 12 Apr 2007 14:44:35 GMT</pubDate><guid>http://pubsindex.trb.org/view/802397</guid></item><item><title>Development and Performance Evaluation of a Revenue Collection System Based on Vehicle Miles Traveled</title><link>http://pubsindex.trb.org/view/780593</link><description><![CDATA[The State of Oregon is heavily dependent on fuel tax revenues to maintain roads. Several technological developments, including the introduction and use of more fuel-efficient vehicles, will have a dramatic effect on fuel tax revenues in the near future. In response to these trends, Oregon House Bill 3946 mandates that the Oregon Department of Transportation (ODOT) begin implementing pilot systems to test alternatives to the current system of taxing highway use through fuel taxes. The Road User Fee Task Force (RUFTF) was created as part of the bill with the mission of “developing a revenue collection design funded through user pay methods, acceptable and visible to the public, that ensures a flow of revenue sufficient to annually maintain, preserve and improve Oregon’s state, county and city highway and road system.” One alternative being considered by the RUFTF employs a fee based on vehicle miles traveled (VMT). This paper describes the development of two working VMT-based prototype technology configurations. This development effort was necessary because commercial-off-the-shelf technology with the functionality required by RUFTF was not available. Multiple concepts for on-vehicle mileage collection devices (using both odometer and Global Positioning System technology) and systems for fee calculation and collection were developed, integrated, and tested as part of the two prototype technology configurations. Results indicate that a VMT-based fee collected via radio frequency communications at service stations is technologically feasible.]]></description><pubDate>Wed, 12 Apr 2006 11:37:56 GMT</pubDate><guid>http://pubsindex.trb.org/view/780593</guid></item><item><title>EVALUATING MOISTURE SENSORS AND MONITORING SEASONAL MOISTURE VARIATION IN LOW-VOLUME ROADS</title><link>http://pubsindex.trb.org/view/695886</link><description><![CDATA[For the past several years, the Forest Service of the U.S. Department of Agriculture has been evaluating a quantitative technique for the application and removal of load restrictions by observing relationships among pavement stiffness, pavement damage, soil moisture, and seasonal freezing and thawing. Laboratory tests of time-domain reflectometry (TDR) and radio frequency (RF) sensors showed them to be reasonably accurate and repeatable when compared with known moisture values in several soil types.  Laboratory tests of the probes under repeated adverse freeze-thaw cycling showed the probes to be durable. Although the field survival rate of TDRs surpassed that of RFs, analysis of field data collected at seven locations in four national forests showed that permanently installed sensors strategically located on a forest road network can provide an affordable method for quantitatively determining the beginning and end of critical periods of pavement weakening associated with spring thaw.  This information would be useful in administering periods of spring-thaw load restrictions.  The laboratory and field test programs conducted are outlined.  The field technique is applicable to any secondary road subjected to seasonal freezing.]]></description><pubDate>Thu, 08 Nov 2001 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/695886</guid></item><item><title>REMOVING SPRING THAW LOAD RESTRICTIONS FROM LOW-VOLUME ROADS: DEVELOPMENT OF A RELIABLE, COST-EFFECTIVE METHOD</title><link>http://pubsindex.trb.org/view/500671</link><description><![CDATA[Low-volume roads in areas of seasonal freezing are highly susceptible to damage from trafficking during spring thaw.  To minimize pavement damage, many agencies and states impose load restrictions during periods in which damage is most likely to occur.  However, the magnitude and duration of reduced or prohibited hauling vary widely among agencies, and an optimal balance between maximizing local economy and minimizing road damage is rarely achieved.  The U.S. Department of Agriculture Forest Service and the U.S. Army Cold Regions Research and Engineering Laboratory are evaluating a quantitative technique for removing load restrictions by developing correlations between pavement stiffness and soil moisture.  Laboratory tests of the moisture sensors showed them to be accurate and repeatable under adverse freeze-thaw cycling.  Preliminary analysis of field data showed that permanently installed time domain reflectometry and radio frequency soil moisture sensors strategically located throughout the forest road network will provide an affordable method for quantitatively determining when to remove load restrictions.  Load restriction practices are reviewed, economic ramifications on the forest industry are briefly discussed, and laboratory and field test programs conducted to monitor soil moisture and pavement stiffness are outlined.  In addition, instrumentation used for the study is described, observations from one of four national forest pavement test sites are presented, and the ongoing research to develop a method to remove load restrictions is discussed.]]></description><pubDate>Wed, 26 May 1999 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/500671</guid></item><item><title>AUTOMATIC VEHICLE IDENTIFICATION TECHNOLOGY APPLICATIONS TO TOLL COLLECTION SERVICES</title><link>http://pubsindex.trb.org/view/578117</link><description><![CDATA[Intelligent transportation systems technologies are being developed and applied through transportation systems in the United States.  An example of this type of innovation can be seen on toll roads where a driver is required to deposit a toll in order to drive on a toll road.  To automatically process toll services, automatic vehicle identification (AVI) technologies should be developed and implemented.  A summary is presented of a study that focused on the performance analysis of three types of AVI technologies that could be used for toll collection applications on the Crosstown Expressway and the Veterans Expressway in Hillsborough County, Florida.  The three AVI technology types were optical/laser scanner, radio frequency, and inductive loop.  The study aimed at analyzing the total average delay and AVI market share due to the usage of AVI technologies.  Delay performance and market share resulting from the application of each AVI technology type were used to compare the effects of different AVI technology types.  The analysis was based on computer simulation using an AVI lane choice model (demand model) and a delay model (performance model) with the data collected from the two toll roads in Hillsborough County. From the simulation results, a cost-benefit analysis was performed to evaluate the impacts of AVI technologies on the ratio of benefit over cost.  Results of the cost-benefit analysis can be used to determine the optimal configuration of AVI lanes and manual lanes.  A procedure is provided that can be used for planning and designing AVI technologies used in toll service.]]></description><pubDate>Tue, 04 Nov 1997 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/578117</guid></item><item><title>FEASIBILITY STUDY OF ITS DRIFTING-OUT-OF-LANE ALERT SYSTEM</title><link>http://pubsindex.trb.org/view/465173</link><description><![CDATA[This Innovations Deserving Exploratory Analysis (IDEA) project investigated two concepts for low-cost automated systems that can sense when a vehicle drifts out of its lane and then alert the driver.  One system was based on vehicle-mounted infrared (IR) sensors and the other on radio-frequency (RF) sensors, both of which can detect reflective paint stripes on the lane boundaries.  Results indicate that both technologies may be used to detect suitable paint stripes, but further refinement is necessary, and important issues remain to be addressed.  It is recommended that further study of the RF technology be conducted.  The IR technology has certain benefits over RF methods, but is not suitable in inclement weather conditions.]]></description><pubDate>Mon, 14 Oct 1996 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/465173</guid></item><item><title>IMPACT OF RADIO FREQUENCY REFARMING ON TRANSIT COMMUNICATIONS</title><link>http://pubsindex.trb.org/view/461828</link><description><![CDATA[This report will be of interest to general managers, operations managers, and communications specialists responsible for communications systems within transit and paratransit organizations.  The report provides information concerning the Federal Communications Commission (FCC) rules governing the refarming of the land mobile radio spectrum and their impacts on current and future transit communication system requirements. The report contains a nontechnical executive summary that describes the rules issued in June 1995 by the FCC regarding the refarming of radio frequencies, provides an overview of the impacts of radio frequency refarming, and offers potential courses of action for transit and paratransit systems.  In addition, the report provides more detailed technical information for communications specialists, and includes several examples of potential cost impacts to transit and paratransit systems.]]></description><pubDate>Wed, 08 May 1996 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/461828</guid></item><item><title>COMMUNICATIONS ARCHITECTURE FOR EARLY IMPLEMENTATION OF INTELLIGENT VEHICLE HIGHWAY SYSTEMS</title><link>http://pubsindex.trb.org/view/385084</link><description><![CDATA[Communications--wireless communications in particular--is a critical component of intelligent vehicle highway systems (IVHS).  It is costly when viewed from two different angles: first, its dependence on using the scarce natural resources called radio frequency (RF) spectrum, and second, the actual cost of implementing the necessary infrastructure and the required (in-vehicle) user equipment.  On the other hand, it is imperative, for the success of the national IVHS program, to plan a near-term IVHS architectural implementation to show positive first-user benefits.  Bearing in mind the above constraints, it is natural to think of designing an IVHS communications architecture that makes use of existing infrastructures for other communications services.  This strategy enables more efficient use of the RF spectrum while it reduces the total cost of services by sharing the communications infrastructure and end-user equipment.  A communications architecture and end-user equipment.  A communications architecture is proposed for IVHS called the Subsidiary Communications Authority Traffic Information Channel (STIC), based on the widely available FM radio broadcast services' infrastructures by making use of FM subcarrier technology.  This preliminary design also shows that STIC has a higher data transmission capacity than any other existing FM subcarrier broadcast system and that it has the potential to meet the one-way outbound (broadcast) data transmission capacity needs of IVHS for the next few years.  In addition, STIC architecture is capable of being scaled up in the future.]]></description><pubDate>Tue, 22 Feb 1994 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/385084</guid></item><item><title>AUTOMATIC EQUIPMENT IDENTIFICATION SYSTEMS FOR INTERMODAL OPERATIONS - A RAILROAD PERSPECTIVE</title><link>http://pubsindex.trb.org/view/300523</link><description><![CDATA[There are two distinct aspects of intermodal terminal inventory systems:  terminal inventory control, which deals with the routine operation of locating equipment within the terminal, and automated equipment identification (AEI), which deals with the problem of encoding each trailer which enters a terminal and when it leaves.  There are several types of AEI technologies in use:  temporary bar codes (paper labels); optical character recognition; and radio frequency tags, temporarily or permanently affixed to the vehicle.  The Association of American Railroads and the Massachusetts Institute of Technology conducted a survey of railroads to determine what the railroad requirements are for an AEI system.  The survey found that few terminals have individually marked parking spaces and that virtually no terminals assign equipment to specific areas.  Inventories are performed from 0 to 3 times per day, requiring 0.5 to 24 man-hours to perform.  Included in this paper are responses to questions posed to the railroads about the severity of their problems in locating equipment in the terminals and their operations of AEI systems to expedite inventory control.]]></description><pubDate>Thu, 31 Aug 1989 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/300523</guid></item><item><title>A RADIO-FREQUENCY DEICING SYSTEM FOR THIRD RAILS</title><link>http://pubsindex.trb.org/view/270080</link><description><![CDATA[A radio-frequency (RF) deicing system for third rails has been proposed. It consists of an RF generator, transmission lines, a work coil, and a mechanical scraper, all mounted on a train. The system definition of such a setup is presented. Several coil configurations are studied. Experimental setups for static calorimeter tests, dynamic temperature rise tests, and deicing tests are described, and results are reported. With 50-kW 185-kHz RF generator power, successful deicing was accomplished up to a speed of 43.5 km/hr at an ambient temperature of -2.2ousC using a ferrite-core coil. Finally, possible future improvements to the system are discussed.]]></description><pubDate>Wed, 30 Apr 1986 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/270080</guid></item><item><title>RADIO FREQUENCY DEICING OF COLLECTOR RAILS FOR AGT SYSTEMS</title><link>http://pubsindex.trb.org/view/189313</link><description><![CDATA[Radio frequency (RF) induction heating has been proposed as an alternative deicing technique for automatic guideway transit (AGT) collector rails under adverse weather conditions.  The concepts of a practical RF deicing system are discussed.  A working frequency of 450 kHz is used for the RF generator, and 430 magnetic stanless steel is selected as the rail-capping material for efficient coupling.  Experimental setup for a model RF deicing system is described.  With 2.5-kW RF generator power, successful deicing was accomplished up to a rail speed of 3.2 km/h for rail temperatures as low as -30 deg C.  The performance of this test system is assessed, and possible future improvements are suggested.  (Author)]]></description><pubDate>Thu, 30 Jun 1983 00:00:00 GMT</pubDate><guid>http://pubsindex.trb.org/view/189313</guid></item></channel></rss>