Download or read book Evaluation of ODOT Roadway weather Sensor Systems for Snow Ice Removal Operations written by Helmut T. Zwahlen and published by . This book was released on 2006 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Evaluation of ODOT Roadway weather Sensor Systems for Snow Ice Removal Operations RWIS written by Gayle F. Mitchell and published by . This book was released on 2006 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study addressed pretreatment protocol for winter maintenance of roadways using brine. Information regarding pretreatment was assessed from surveys of personnel in state departments of transportation and county garages in Ohio. Field durability studies of various applications of brine were conducted on Portland cement concrete and asphalt concrete pavements in Ohio. Over three winter seasons, weather events and resulting pavement conditions were documented during pretreatment and during the subsequent events using visual and limited road grip tester (RGT) assessment. In addition, extensive laboratory studies were undertaken to supplement the field investigations. Integration of the findings resulted in a decision tree to aid in operational planning and pretreatment.

Download or read book Evaluation of ODOT Roadway weather Sensor Systems for Snow and Ice Removal Operations written by and published by . This book was released on 2003 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: Road Weather Information System (RWIS) pavement sensors from three vendors were evaluated under controlled conditions in a climate chamber. The chamber had a maximum cooling rate of about 5.6°C in the first 15 minutes (about 15.8°C in the first hour) and could cool from a room temperature of about 22°C to a minimum temperature of approximately -17°C in about 15 hours. One vendor supplied an active (cooling/heating cycle) sensor with an active-passive sensor as a combined system, and the other two supplied passive sensors. Each sensor was installed in a concrete block cut from a bridge deck and positioned in a large climate-controlled chamber. The sensors were tested for accuracy and precision of temperature, freezing point determination, chemical percentage or index, surface status, and liquid depth, where appropriate. Testing parameters included salt type (pure water, 7%, 13%, & 19% NaCl in water, 17% & 30% CaCl2 in water, and two mixtures of the two salts in solution), and liquid depth (0.5 mm, 1.5 mm, 3 mm, 6 mm). The temperature in the chamber was reduced until the liquid froze or a minimum temperature below -15°C was attained. Independent temperature probes were placed on and near the block for comparison to sensor readings. Results obtained for the three sensors varied considerably. The surface status (wet/dry) reported by Vendor C's sensor was accurate at the beginning of each run 100% of the time, but accurate only 81% of the time at the end of the run. For Vendor A the corresponding accuracy rates were 97% and 92%. Vendor B's more detailed scheme was accurate only 19% of the time at the beginning of each run and 47% at the end. The surface temperature reported by each passive or active-passive sensor during cooling of the climate chamber was found to lag behind that measured by the independent probes placed in the liquid and on the surface of the block. The average maximum lag in temperature and the average time at which it was observed for each vendor were: Vendor A: 5.6°C at 150 minutes, Vendor B: 4.0°C at 157 minutes, and Vendor C: 7.0°C at 128 minutes. Vendor A's active sensor freezing point values varied considerably from expected values, and also changed during runs. The chemical percentage reported by Vendor B's passive sensor showed an appropriate variation with NaCl concentration, though at higher concentrations the initial reported concentration was low; this bias was also reflected in the freezing point values computed by the system. Percentages were less accurate with CaCl2 or NaCl-CaCl2 mixtures, for which the system was not calibrated. Vendor C's chemical index did not appear to correlate with salt concentration at all. Because of these results, none of these sensors in their present state is recommended for use at the present time. Any future sensor deployment should be contingent on the ability of the chosen sensor to perform those functions considered necessary by ODOT.

Download or read book Evaluation of ODOT Roadway weather Sensor Systems for Snow and Ice Removal Operations written by Gayle F. Mitchell and published by . This book was released on 2003 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Winter Highway Operations written by Steven M. Conger and published by Transportation Research Board. This book was released on 2005 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Effectiveness of RWIS Bridge Temperature Simulators written by and published by . This book was released on 2007 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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

Download or read book Strategies to Mitigate the Impacts of Chloride Roadway Deicers on the Natural Environment written by Laura Fay and published by . This book was released on 2013 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: "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.

Download or read book Ohio Documents written by and published by . This book was released on 2003 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Future Direction of the Roadway Weather Information System RWIS at PennDOT written by Gannett Fleming, Inc and published by . This book was released on 2007 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Road Weather Information Systems Implementation guide written by and published by . This book was released on 1993 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Strategic Highway Research Program sponsored research into the use of road weather information systems (RWIS) for highway snow and ice control. The research indicated that the use of RWIS technologies can improve the efficiency and effectiveness as well as reduce the costs of highway winter maintenance practices. Volume 2, the implementation guide supplements Volume 1, the research report, which documents the research.

Download or read book Road Weather Information Systems written by S. Edward Boselly and published by Strategic Highway Research Program (Shrp). This book was released on 1993 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Strategic Highway Research Program sponsored research into the use of road weather information systems (RWIS) for highway snow and ice control. The research indicated that the use of RWIS technologies can improve the efficiency and effectiveness as well as reduce the costs of highway winter maintenance practices. Volume 2, the implementation guide supplements Volume 1, the research report, which documents the research.

Download or read book Concepts for Managing Freeway Operations During Weather Events written by and published by . This book was released on 2007 with total page 186 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Monitoring and Improving Roadway Surface Conditions for Safe Driving Environment and Sustainable Infrastructure written by Ching-Yao Chan and published by . This book was released on 2012 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt: "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.

Download or read book Evaluation of the GPS AVL Systems for Snow and Ice Operations Resource Management written by William H. Schneider (IV) and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Snow and ice management is the single largest expenditure in the maintenance budget for the Ohio Department of Transportation (ODOT) with an annual cost including labor, equipment, and materials reaching approximately $86 million (ODOT, 2013). One method to increase the efficiency of operations is the implementation of a Global Positioning System (GPS) and Automatic Vehicle Location (AVL) resource management system. Phase One of the project, was to implement 22 trucks with systems that work with the hydraulic system on the truck. During this phase, the research team was able to implement one system that works with both primary hydraulic systems in the ODOT fleet. With success in Phase One, Phase Two was developed to scale-up the fleet from 22 to 187 trucks throughout the state. The deliverables of this project are the details of installing and troubleshooting the system and the website developed for ODOT and with ODOT. The website allows real-time data and historical data for the truck location and road conditions. The website is able to rely various data platforms depending on what ODOT wants to implement. The cost of the systems will vary depending on the level of detail the end users would like to receive. More sensors requires more capital, maintenance and calibration cost.

Download or read book Synthesis of Highway Practice written by National Cooperative Highway Research Program and published by . This book was released on 2005 with total page 694 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of Prototypes of a Portable Road Weather Information System written by Meha Kainth and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Weather conditions have significant impact on road safety and roadway maintenance operations. Road Weather Information Systems (RWIS) play a significant role in providing weather and surface conditions to transportation agencies to monitor weather events. Fixed installations of RWIS are used for weather and pavement surface monitoring. However, permanent fixture installations may not be feasible due to reasons such as cost, accessibility to the site, siting concerns, and terrain. Portable RWIS provide a cost-effective solution in areas where permanent weather station installation is not possible. This study discusses use and benefits of the portable RWIS and outlines the issues involved in building them. This thesis presents the system design for building prototypes of two portable RWIS systems to be used by Massachusetts Department of Transportation (MassDOT). Portable RWIS consist of weather sensors and pavement sensors installed on a trailer-based platform and operate on solar power. The RWIS equipment mounted on trailers consists of non-invasive pavement sensors, wind sensor, precipitation sensor, atmospheric pressure sensor, humidity and dew point sensor and data logger to transmit data from the sensors to a central server. RWIS equipment from two different manufacturers have been selected. The two systems have been evaluated for their cost, operability, ease- of-use and deployability. A field study of two portable RWIS has been conducted to test accuracy of the data collected by these systems and the results have been evaluated. Characterizing the issues involved in developing such portable systems provide insights into situations where these systems may be most applicable.

Download or read book Safety Effects of Road Weather Information Systems RWIS written by Davesh Sharma and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In countries like Canada and the United States, where most of the population lives in snowy regions, winter road maintenance (WRM) has become a significant challenge. Hundreds of people are killed, and thousands are injured every year due to inclement winter weather conditions. To combat this, transportation agencies spend a significant amount of their budget on conducting and maintaining WRM activities. Considering their limited budget and resources, it is indispensable to strategize their investments in equipment, labour, and material without jeopardizing commuter safety. One of the most advanced techniques used for efficient mobilization of WRM services is Road Weather Information Systems (RWIS) - a critical highway intelligent transportation system (ITS) infrastructure. These systems have long been favoured by many North American and European highway authorities as they provide real-time and near-future road condition information collected using roadside sensors during the winter months. Information disseminated by individual RWIS stations is collectively used not only to proficiently organize WRM operations but also to promote safe travel and provide traveller information during adverse weather events. However, the high installation and operational costs of RWIS have necessitated the need to quantify their cost-effectiveness, particularly in improving traffic safety. Limited past efforts have been made to quantify the sole benefits of RWIS, but most analyses were either qualitative in nature or used a naïve safety evaluation technique that resulted in generating less conclusive findings. Acknowledging the importance of determining their benefits as well as a large gap that exists in current methodologies, this thesis aims to develop a unique methodological framework that can be readily used to evaluate and quantify the sole safety effects of RWIS. In particular, this thesis attempts to tackle and answer two research questions: first, whether implementing RWIS stations reduces winter weather collisions and how much reduction can be expected; second, whether RWIS stations are a cost-effective countermeasure with explicit monetary benefits. These questions were answered by conducting a safety evaluation of RWIS stations and an economic analysis. Safety evaluation of RWIS stations was conducted by using one of the most established and statistically defendable methods used in traffic safety studies, namely, the before-and-after Empirical Bayes (EB) approach was used to perform safety evaluation of RWIS stations. A methodology was developed, and a state-wide investigation of RWIS stations in the state of Iowa was conducted. Geographic Information Science (GIS) based techniques were used for the preparation of intensive geospatial datasets required for calibration and validation of safety performance function (SPF). Furthermore, Yearly Calibration Factors (YCFs) were also locally calibrated using large-scale spatial data, where network-based service area analysis using GIS played a crucial role in selecting treatment and reference sites. The results of safety evaluation were used to conduct a detailed economic analysis and Benefit-to-Cost ratios (BCRs) were estimated as a parameter to assess the economic viability of RWIS stations. One-time installation cost, operations cost, and up-gradation cost for each RWIS station were compared with the monetary value safety benefits. Utilizing the developed methodology in this thesis, the sole effectiveness of implementing RWIS was quantified to establish RWIS as a safety countermeasure. The findings from the case study showed safety effectiveness of RWIS that ranged from 31.53% to 88.23%, whereby implying that a significant portion of winter weather collisions was reduced after RWIS implementation. The BCRs of the stations ranged from 7.51 to 34.16, indicating a significant amount of safety benefits compared to the cost of RWIS. The research findings suggest that RWIS stations are an economically viable safety countermeasure, and that transportation professionals and highway authorities can now make more informed decisions on furthering RWIS implementations to improve the safety and mobility of the winter traveling public. The main contributions of this thesis are three-fold. First, the safety effectiveness of RWIS stations was quantified for the first time in the literature using the state-of-the-art EB method with large-scale and multi-year datasets. Second, SPF was locally developed during the process, which is transferable and can be readily used for safety investigations at regions with similar geographical and weather characteristics. Finally, the economic viability of RWIS was quantified using a formal economic analysis at high granularity, which has been absent from the RWIS literature.