Evaluation of ODOT Roadway/weather Sensor Systems for Snow & Ice Removal Operations PDF Download
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Author: Helmut T. Zwahlen
Publisher:
ISBN:
Category : Automobile driving in winter
Languages : en
Pages : 190
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Book Description
The major objective of the study was to develop a procedure to determine the level of service using the RWIS speed measurements. The procedure developed can be used by ODOT to evaluate winter maintenance activities and for winter maintenance decision making. Average traffic speeds for five minute intervals were measured using NuMetrics road sensors and they were related to the pavement and driving conditions. In addition speed data from two other studies was used. The pavement conditions were determined by conducting surveys at rest area buildings using a questionnaire form. It was found that the average traffic speeds were significantly lower during a major snow event even when periodic plowing and salting was done. The average speeds decreased almost linearly for the period of the snow storm reached the minimum and then climbed back slowly towards higher speeds. The speeds appear to be a fairly sensitive measure to judge the condition of the pavement. The motorist judgments about the pavement condition and their perception of the safety of driving decreases during a rather severe winter storm which is mirrored in the speed decrease. It appears from the survey that about two thirds of the motorists judge the deterioration of the road conditions and the inadequate level of road maintenance during a winter storm as bad or moderately bad. The responses obtained for the car and the truck drivers are fairly close to each other indicating that both groups can judge bad road condition equally well. The observed road conditions appear to influence the drivers in terms of how they subjectively feel about the level of safety and stress experienced during driving in the winter storm. A simple procedure was developed for winter maintenance management to determine the condition of the road (freeways) based on the average speeds observed by the RWIS sensors. If the average winter speed of the traffic is equal or greater than the historical established wet/salted pavement speed, the level of service is considered adequate. According to the Swiss study, the wet/salted surface winter speeds are about 85% of the dry surface speeds for freeways and 96 % for city streets. If the average winter speed is below the wet/salted surface speed, the level of service is considered inadequate. Any speed less than 50% of the wet/salted surface speed indicates fairly bad road conditions and an extremely inadequate level of service. It should be noted that the winter pavement conditions can be highly dynamic. Depending on the rate of accumulation of snow, frequency of the snow plowing, length of the snow plow route, the pavement condition can improve and deteriorate a number of times during a winter storm. The level of service can get worse even with maximum snow plowing and salting effort in a situation with a high rate of snow accumulation. The winter speeds observed as a percentage of the average dry surface speed can be correlated with the level of service. A relatively more fine graduation of the level of service as a function of the percentage of the average dry surface speed is proposed in the recommendations of the report.
Author: Helmut T. Zwahlen
Publisher:
ISBN:
Category : Automobile driving in winter
Languages : en
Pages : 190
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Book Description
The major objective of the study was to develop a procedure to determine the level of service using the RWIS speed measurements. The procedure developed can be used by ODOT to evaluate winter maintenance activities and for winter maintenance decision making. Average traffic speeds for five minute intervals were measured using NuMetrics road sensors and they were related to the pavement and driving conditions. In addition speed data from two other studies was used. The pavement conditions were determined by conducting surveys at rest area buildings using a questionnaire form. It was found that the average traffic speeds were significantly lower during a major snow event even when periodic plowing and salting was done. The average speeds decreased almost linearly for the period of the snow storm reached the minimum and then climbed back slowly towards higher speeds. The speeds appear to be a fairly sensitive measure to judge the condition of the pavement. The motorist judgments about the pavement condition and their perception of the safety of driving decreases during a rather severe winter storm which is mirrored in the speed decrease. It appears from the survey that about two thirds of the motorists judge the deterioration of the road conditions and the inadequate level of road maintenance during a winter storm as bad or moderately bad. The responses obtained for the car and the truck drivers are fairly close to each other indicating that both groups can judge bad road condition equally well. The observed road conditions appear to influence the drivers in terms of how they subjectively feel about the level of safety and stress experienced during driving in the winter storm. A simple procedure was developed for winter maintenance management to determine the condition of the road (freeways) based on the average speeds observed by the RWIS sensors. If the average winter speed of the traffic is equal or greater than the historical established wet/salted pavement speed, the level of service is considered adequate. According to the Swiss study, the wet/salted surface winter speeds are about 85% of the dry surface speeds for freeways and 96 % for city streets. If the average winter speed is below the wet/salted surface speed, the level of service is considered inadequate. Any speed less than 50% of the wet/salted surface speed indicates fairly bad road conditions and an extremely inadequate level of service. It should be noted that the winter pavement conditions can be highly dynamic. Depending on the rate of accumulation of snow, frequency of the snow plowing, length of the snow plow route, the pavement condition can improve and deteriorate a number of times during a winter storm. The level of service can get worse even with maximum snow plowing and salting effort in a situation with a high rate of snow accumulation. The winter speeds observed as a percentage of the average dry surface speed can be correlated with the level of service. A relatively more fine graduation of the level of service as a function of the percentage of the average dry surface speed is proposed in the recommendations of the report.
Author: Gayle F. Mitchell
Publisher:
ISBN:
Category : Deicing chemicals
Languages : en
Pages : 324
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Book Description
The Ohio Department of Transportation (ODOT) has initiated pretreatment as an integral part of a winter management strategy. Currently forty gallons per lane mile of 23% salt brine (NaCl) by weight is applied at a minimum frequency of two times per week when conditions warrant. In order for ODOT to develop the most effective plan for pretreatment, an in-situ study to provide data on decay of brine on trafficked pavement was needed. Objectives included a survey of other state DOT's pretreatment protocols, laboratory studies to discern brine concentrations that precluded ice formation, brine decay with traffic and time on several pavements, and correlation of laboratory and field data. Ten of the 28 state DOTs responding to the survey regarding pretreatment protocol applied NaCl two to 24 hours prior to a storm; two states used surface type, traffic volume, and air temperatures for decision making. The survey reinforced the need of laboratory and field studies. In the laboratory, release temperatures of the ice/surface bond at various brine concentrations were obtained utilizing conductivity and physical observation techniques. Laboratory tests with the field brine measurement instrumentation (SOBO-20 by Boschung Megatronic AG) provided correction factors for the field data on AC and PCC pavements. Sodium chloride brine was applied and measured in-situ in mass per area at five field sites (ATH-50 PCC, ATH-50 AC, DEL-23 PCC, DEL-23 AC, and ATH-33 AC) encompassing at least four sections at each site. Initial losses and decay due to time/traffic were obtained. Of the five test sites, AC (micro seal), AC (NOVA chip), and a transversely grooved PCC pavement provided statistically valid data to develop residual decay equations as a function of time/traffic. Field decay of brine was incorporated into laboratory brine/ice/specimen bonding temperature findings to determine the effective ice prevention temperatures as a function of time/traffic for AC and PCC at standard application rates.
Author: Steven M. Conger
Publisher: Transportation Research Board
ISBN: 0309097479
Category : Technology & Engineering
Languages : en
Pages : 76
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Book Description
TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 344: Winter Highway Operations examines changes that occurred between 1994 and 2004 to practices and strategies used to control the impacts of winter weather on the safe and efficient movement of traffic.
Author:
Publisher:
ISBN:
Category : Ohio
Languages : en
Pages : 94
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Book Description
Author: Akira Otsuki
Publisher: Elsevier
ISBN: 0323984789
Category : Science
Languages : en
Pages : 842
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Book Description
Non-Destructive Material Characterization Methods provides readers with a trove of theoretical and practical insight into how to implement different non-destructive testing methods for effective material characterization. The book starts with an introduction to the field before moving right into a discussion of a wide range of techniques that can be immediately implemented. Various imaging and microscopy techniques are first covered, with step-by-step insights on characterization using a polarized microscope, an atomic force microscope, computed tomography, ultrasonography, magnetic resonance imaging, infrared tomography, and more. Each chapter includes case studies, applications, and recent developments. From there, elemental assay and mapping techniques are discussed, including Raman spectroscopy, UV spectroscopy, atomic absorption spectroscopy, neutron activation analysis, and various others. The book concludes with sections covering displacement measurement techniques, large-scale facility techniques, and methods involving multiscale analysis and advanced analysis. - Provides an overview of a wide-range of NDT material characterization methods, strengths and weaknesses of these methods, when to apply them, and more - Includes eddy current sensing and imaging, ultrasonic sensing and imaging, RF and THz imaging, internet and cloud-based methods, among many others - Presents case studies, applications and other insights on putting these methods into practice
Author: Laura Fay
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 110
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Book Description
"TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 449 : Strategies to Mitigate the Impacts of Chloride Roadway Deicers on the Natural Environment documents the range of methods, tools, and techniques used by transportation agencies to minimize the environmental impact of chloride-based roadway deicers"--Publisher's description.
Author: Gannett Fleming, Inc
Publisher:
ISBN:
Category : Traffic safety
Languages : en
Pages : 250
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Book Description
Author:
Publisher:
ISBN:
Category : Bridges
Languages : en
Pages : 248
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Book Description
Bridge deck simulators (BDSs), 6 in. (15 cm) concrete cubes with an embedded temperature probe, are intended as a cost-effective substitute for RWIS pavement sensors to represent conditions likely on bridge decks in an area near an RWIS station. In this study, the effectiveness of the BDSs to predict the temperature on nearby bridge decks was evaluated. Nine sites were selected by ODOT across the state of Ohio (six in northeastern region and three in southwestern region) which were instrumented with BDSs and Nu Metrics pavement sensors on the bridge deck and (with one exception) on the road surface off the bridge. The use of BDSs appears to be unique to Ohio. A survey in the state of Ohio indicated little use was being made of BDS information. RWIS temperature data collected at five minute intervals during winter season 2004-2005 were analyzed and the unusable data were weeded out by removing redundant entries, blank or incomplete entries, extreme temperature readings, and entries where sensor data were not updated. Correlation analysis was performed on the "cleaned" data from the nine sites for the air and BDS temperatures versus bridge deck and road temperatures, and also for air versus BDS temperatures. Separate correlations were made with all-day data and with nighttime data free of solar radiation effects. For both all-day and nighttime data, the BDS was found to better correlate with bridge deck and road temperatures than was the air temperature. The nighttime data were then further analyzed to determine 90%, 95%, 99% prediction limits for the prediction of bridge deck and road temperatures based on the BDS and air temperature values. Again, the prediction limits for bridge and road temperatures using the BDS were generally tighter than when using air temperature. Finite element analyses (FEA) were performed for the nine sites using ALGOR V18 software to investigate the temperature behavior of the bridge deck and the BDS for the air temperature profiles reflecting extreme positive and negative temperature gradients recorded at each site. The FEA modeling provided information about how the BDS and the bridge deck temperature change as a function of the air temperature and time. Larger concrete cube sizes, up to 24 in. (61 cm) on a side, were investigated with FEA in an exploratory manner. The 24 in. (61 cm) cube almost exactly matched the simulated bridge deck temperature profiles under a variety of air temperature loads. The FEA temperature profiles showed that the existing BDS does not always closely represent the true temperature behavior of the bridge deck, but that a concrete cube 4 times larger on a side would compare much better. Yearly training of maintenance personnel in the use of the BDS and RWIS is recommended
Author: Ching-Yao Chan
Publisher:
ISBN:
Category : Pavements
Languages : en
Pages : 334
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Book Description
"Toward the goal of reducing collisions while maintaining the integrity and sustainability of roadways, separate projects in both France and California in recent years have been developed to achieve the following objectives: evaluating the effectiveness of."--Documentation page abstract.
Author:
Publisher:
ISBN:
Category : Automobile driving in bad weather
Languages : en
Pages : 186
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Book Description
The goal of this research was to help the Texas Department of Transportation (TxDOT) develop a structured, systematic approach for managing traffic during weather events. The focus in this research project was on common weather events - such as fog, high winds, heavy rains, and snow and ice storms - that impact traffic operations day-to-day. First, the authors conducted a survey of selected TxDOT districts to determine what information traffic management center (TMC) operators need to manage traffic operations during weather events. Through a review of the existing literature, the authors assessed systems and technologies that other states have deployed to manage traffic during weather-related events. They reviewed the current state of weather-related detection and monitoring technologies. Using historical traffic detector and weather information, they assessed the magnitude of the impact of different weather events on traffic operations. Using all this information, the authors developed concepts of operations for how TMC operators should respond to different types of weather-related events, including limited visibility conditions, ponding and flash flooding, high winds, severe thunderstorms, tornados, and winter storms. They developed a catalog of advisory, control, and treatment strategies (or ACTS) that operators could use to manage traffic operations during weather events.
